mathematics MCQs
Showing 50 questions (Total: 16798)
Which of the following fractions is the largest?
Correct Answer:
D: 7/8
Explanation:
Which of the following fractions is the largest? Correct Answer 7/8 63/80 = 63×1 /80×1 = 63/80 31/40 = 31 × 2 /40×2 = 62 /80 13/16 = 13×5/16×5 = 65/80 7/8 = 7 × 10 /8×10 = 70/80 [ বৃহত্তম ]
The square root of 64009 is :
Correct Answer:
A: 253
Explanation:
The square root of 64009 is : Correct Answer 253 Hints: 64009 কে রুট করলে হয় 253 সুতরাং সঠিক উত্তর: 253
Two pipes A and B can fill a tank in 6 hours and 4 hours respectively. If they are opened on alternate hours and if pipe A is opened first, in how many hours, the tank shall be full ?
Correct Answer:
C: 5
Explanation:
Two pipes A and B can fill a tank in 6 hours and 4 hours respectively. If they are opened on alternate hours and if pipe A is opened first, in how many hours, the tank shall be full ? Correct Answer 5 (A + B) ' 2 hours work when open d = 1/6 + 1/4 = 5/12 (A + B) 4 hours work when open = 5/12 × 2 = 5/6 Remaining work 1 - 5/6 = 1/6 Now, its A turn in 5th hour 1/6 work will be done by A in 1 hour Total time = 4 + 1 = 5 hours
A train 108 m long moving at a speed of 50 km/hr crosses a train 112 m long coming from opposite direction in 6 seconds. The speed of the second train is --
Correct Answer:
D: 82 km/hr
Explanation:
A train 108 m long moving at a speed of 50 km/hr crosses a train 112 m long coming from opposite direction in 6 seconds. The speed of the second train is -- Correct Answer 82 km/hr ধরি, দ্বিতীয় ট্রেনটির গতি x km/hr 6/60× 60 = (108/1000) + (112 /1000) / x + 50 1/600 = ( 220/1000) / x + 50 1/600 = 22/100( x + 50) 1/6 = 22/ x + 50 x + 50 = 6 × 22 x = 132 - 50 x = 82
(1000)^7/10^18 = ?
Correct Answer:
C: 1000
Explanation:
(1000)^7/10^18 = ? Correct Answer 1000 Hints : (1000)2/1018 = {(10)3}7/1018 = 1021/1018 = 1021 - 18 = 103 = 1000
In a 200 metres race A beats B by 35 m or 7 seconds. A's time over the course is :
Correct Answer:
A: 33 sec
Explanation:
In a 200 metres race A beats B by 35 m or 7 seconds. A's time over the course is : Correct Answer 33 sec Hints : B runs 35m in 7 sec B covers 200 m in ( 7/35 × 200) = 40 sec B's time over the course = 40 sec A's time over the course = (40 - 7) sec = 33 sec
The average of 7 consecutive numbers is 20. The largest of these number is ---
Correct Answer:
A: 23
Explanation:
The average of 7 consecutive numbers is 20. The largest of these number is --- Correct Answer 23 ধরি, সংখ্যাগুলো, x - 3, x - 2, x - 1, x + 1, x + 2, x + 3 x - 3 + x - 2 + x - 1 + x + x + 1 + x + 2 + x + 3/7 = 20 7x/7 = 20 x = 20 বৃহত্তম সংখ্যাটি = x + 3 = 20 + 3 = 23
2% of 2=?
Correct Answer:
D: 0.04
Explanation:
2% of 2=? Correct Answer 0.04 2 এর 2% = 2 এর 2/100 = 4/100 = 0.04
617+6.017+0.617+6..0017 = ?
Correct Answer:
C: 629.6357
Explanation:
617+6.017+0.617+6..0017 = ? Correct Answer 629.6357 Hints : 617 + 6.017 + .617 + 6.0017 = 629.6357 ( The first digit is 617, the sum would definitely be over 617)
If 15% of 40 is greater than 25% of a number by 2, then the number is :
Correct Answer:
B: 16
Explanation:
If 15% of 40 is greater than 25% of a number by 2, then the number is : Correct Answer 16 Hints : 15 % of 40 = 25 % of number + 2 15 × 40/100 - 2 = 25/100 × number 6 - 2 = 25/100 × number number = 4 × 100/ 25 = 16
The length of a rectangular hall is 5m more than its breadth. The area of the hall is 750m^2. The length of the hall is :
Correct Answer:
D: 30m
Explanation:
The length of a rectangular hall is 5m more than its breadth. The area of the hall is 750m^2. The length of the hall is : Correct Answer 30m Hints : Let, tje breadth be b metre b(b + 5) = 750 b2 + 5b - 750 = 0 b = 25, - 30 breadth = 25 meter and length = 25 + 5 = 30 meter
A can finish a work in 18 days and B can do the same work in half the time taken by A. Then, working together, what part of the same work they can finish in a day ?
Correct Answer:
B: 1/6
Explanation:
A can finish a work in 18 days and B can do the same work in half the time taken by A. Then, working together, what part of the same work they can finish in a day ? Correct Answer 1/6 Hints: Given that B alone can complete the same work in day = half the time taken by A = 9 days A's One day's work = 1/18 B's One days work = 1/9 (A + B)'s one days work = 1/18 + 1/9 = 1/6
At 3.40, the hour hand and the minute hand of a clock form an angle of :
Correct Answer:
C: 130 degree
Explanation:
At 3.40, the hour hand and the minute hand of a clock form an angle of : Correct Answer 130 degree Hints : we use the formula = | 11m/2 - 30h| degree = | 11 × 40 / 2 - 30 × 3 | = 130 degree
A, B and C enter into a partnership. A contributes one-third of the capital while B contributes as much as A and C together contribute. If the profit at the end of the year amounts to Tk. 900, What would C receive?
Correct Answer:
B: Tk. 150
Explanation:
A, B and C enter into a partnership. A contributes one-third of the capital while B contributes as much as A and C together contribute. If the profit at the end of the year amounts to Tk. 900, What would C receive? Correct Answer Tk. 150 ধরি, মোট বিনিয়োগ x টাকা A বিনিয়োগ করে x/3 টাকা B + C = ( x - x/3) = 2x/3 কিন্তু, B এর বিনিয়োগ পরিমান A ও C এর মোট বিনিয়োগের সমান। x/3 + C + C = 2x/3 2C = 2x/3 - x/3 2C = x/3 C = x/6 এবং B = 2x/3 - x/6 = 3x/6 = x/2 A : B : C = x/3 : x/2 : x/6 = 2 : 3 : 1 C এর লাভের পরিমাণ ( 900 এর 1/3 + 2 + 1) = (900 এর 1/6) = 150 টাকা
In a kilometre race, A beats B by 100 m and B beats C by 150 m. In the same race, by how many metres does A beat C?
Correct Answer:
D: 250 m
Explanation:
In a kilometre race, A beats B by 100 m and B beats C by 150 m. In the same race, by how many metres does A beat C? Correct Answer 250 m A, B কে পরাজিত করে 100 মিটারে B,C কে পরাজিত করে 150 মিটারে A,C কে পরাজিত করে ( 100 + 150) = 250 মিটারে।
The average age of 8 men is increased by 2 years when one of them whose age is 24 years is replaced by a woman. What is the age of the woman ?
Correct Answer:
D: 40 years
Explanation:
The average age of 8 men is increased by 2 years when one of them whose age is 24 years is replaced by a woman. What is the age of the woman ? Correct Answer 40 years মহিলাটির বয়স = 8 × 2 + 24 = 16 + 24 = 40 বছর
The sum of two numbers is equal to thrice difference. If the smaller of the numbers is 10 find the other number.
Correct Answer:
B: 20
Explanation:
The sum of two numbers is equal to thrice difference. If the smaller of the numbers is 10 find the other number. Correct Answer 20 ধরি, সংখ্যা দুটি x ও y ; যেখানে x>y x + y = 3 ( x - y) x + 10 = 3 ( x - 10) x + 10 = 3x - 30 2x = 40 x = 20
A makes an article for Tk. 120 and sells it to B at a profit of 25% B sells it to C who sells it for Tk. 198 making a profit of 10%. What profit percent did B make ?
Correct Answer:
B: 20%
Explanation:
A makes an article for Tk. 120 and sells it to B at a profit of 25% B sells it to C who sells it for Tk. 198 making a profit of 10%. What profit percent did B make ? Correct Answer 20% 25 %লাভে A এর বিক্রয়মূল্য ( 120 + 120 × 25/100) টাকা = 150 টাকা। B এর ক্রয়মূল্য = 150 টাকা। 10% লাভে, C এর বিক্রয়মূল্য 110 টাকা হলে ক্রয়মূল্য 100 টাকা C এর বিক্রয়মূল্য 198 টাকা হলে ক্রয়মূল্য ( 100 × 198 /110) = 180 টাকা। B এর বিক্রয়মূল্য 180 টাকা। B এর লাভের হার = ( 180 - 150 /150 × 100) % = ( 30/150 × 100) % = 20%
A sum of Tk. 600 amounts to Tk. 720 in 4 years at Simple Interest. What will it amount to if the rate of interest is increased by 2% ?
Correct Answer:
B: Tk.768
Explanation:
A sum of Tk. 600 amounts to Tk. 720 in 4 years at Simple Interest. What will it amount to if the rate of interest is increased by 2% ? Correct Answer Tk.768 এখানে, I = 720 - 600 = 120 r = 120× 100 / 600 × 4 = 5% 2% বৃদ্ধিতে মুনাফার হার ( 5 + 2) % = 7% I = 600 × 7/100 × 4 = 168 মুনাফা - আসল = 600 + 168 = 768
4500 ×? =3375
Correct Answer:
B: 3/4
Explanation:
4500 ×? =3375 Correct Answer 3/4 4500 × ? = 3375 ∴ ? = 33754500 = 1125 × 31125 × 4 = 3 4
50% of a% of b is 75% of b% of C. Which of the following is C ?
Correct Answer:
B: 0.667a
Explanation:
50% of a% of b is 75% of b% of C. Which of the following is C ? Correct Answer 0.667a 50% of a% of b% = 75% of b% of c 50/100 × a/100 × b = 75/100 × b/100× c 50 a = 75 c c = 50/75 a c = 0.667 a
Which is the following is equal to 3.14 * 10^6 ?
Correct Answer:
C: 3140000
Explanation:
Which is the following is equal to 3.14 * 10^6 ? Correct Answer 3140000 3.14 × 106 = 3.14 × 102 × 104 = 314 × 10000 = 3140000
The sum of first five prime numbers is :
Correct Answer:
D: 28
Explanation:
The sum of first five prime numbers is : Correct Answer 28 প্রথম পাঁচটি মৌলিক সংখ্যার সমষ্টি = 2 + 3 + 5 + 7 + 11 = 28
3 years ago, the average age of a family of 5 members was 17 years. A baby having been born the average age of the family is the same today. The present age of the baby is
Correct Answer:
C: 2 years
Explanation:
3 years ago, the average age of a family of 5 members was 17 years. A baby having been born the average age of the family is the same today. The present age of the baby is Correct Answer 2 years ধরি, বাচ্চাটির বর্তমান বয়স x বছর 17 = 5 × ( 17 + 3) + x /6 102 = 100 + x x = 102 - 100 x = 2
There are two numbers such that the sum of twice the first and thrice the second is 39. While the sum of thrice first and twice the second is 36. The larger of the two is :
Correct Answer:
C: 9
Explanation:
There are two numbers such that the sum of twice the first and thrice the second is 39. While the sum of thrice first and twice the second is 36. The larger of the two is : Correct Answer 9 ধরি, সংখ্যা দুটি x ও y 2x + 3y = 39....... (1) 3x + 2y = 36........... (2) (1) × 3 - (2) × 2 6x + 9y = 117 6x + 4y = 72 5y = 45 y = 9 x = 39 - 27 /2 = 6 বড় সংখ্যাটি 9
(8/88)×8888088=?
Correct Answer:
A: 808008
Explanation:
(8/88)×8888088=? Correct Answer 808008 888 × 8888088 = 111 × 8888088 = 808008
0.002×0.5=?
Correct Answer:
B: 0.001
Explanation:
0.002×0.5=? Correct Answer 0.001 0.002 × 0.5 = 0.0010 = 0.001
The mean of 50 observations was 36. It was found later that an observation 48 was worngly taken as 23. The correct new mean is :
Correct Answer:
C: 36.5
Explanation:
The mean of 50 observations was 36. It was found later that an observation 48 was worngly taken as 23. The correct new mean is : Correct Answer 36.5 "50টি পর্যবেক্ষণের গড় মান 36 ∴ 50 ,, ,, ,, মোট ,, 36 × 50 = 180O আবার, 48 এর স্থলে নেয়া হয়েছে 23 ∴ কম নেওয়া হয়েছে 48 – 23 = 25 ∴ সঠিক মোট মান 1800 + 25 = 1825 ∴ সঠিক গড় মান = 182550 = 36.5"
A man has some hens and cows. If the number of heads be 48 and the number of feet equals 140, then the number of hens will be ----
Correct Answer:
D: 26
Explanation:
A man has some hens and cows. If the number of heads be 48 and the number of feet equals 140, then the number of hens will be ---- Correct Answer 26 "মুরগি ও গরুর মোট সংখ্যা 48টি [কারণ গরু ও মুরগির মাথা 48টি]। এখন, মুরগির পা ২টি করে ও গরু পা ৪টি করে। ধরি, মুরগির সংখ্যা x টি। তাহলে গরুর সংখ্যা (48 – x) টি প্রশ্নমতে, 2x + (48 – 8) 4 = 140 বা, 2x + 48 × 4 – 4x = 140 বা, x + 96 – 2x = 70 বা, 96 – x = 70 বা, 96 – 70 = x ∴ x = 26 অর্থাৎ মুরগি 26টি।"
Find the greatest number that will divide 43, 91 and 183 so as leave the same remainder in each case.
Correct Answer:
A: 4
Explanation:
Find the greatest number that will divide 43, 91 and 183 so as leave the same remainder in each case. Correct Answer 4 " এটি সমাধানের সহজ উপায় হলো উত্তর অপশনগুলো দিয়ে সংখ্যা তিনটিকে ধারাবাহিকভাবে ভাগ করে যাওয়া। এ ক্ষেত্রে অবশ্যই প্রথম অপশন দিয়ে শুরু করতে হবে। কারণ প্রথমটি দিয়ে উত্তর এসে গেলে আর যাচাই করতে হবে না। (অবশ্য যদি একাধিক উত্তর না থাকে)। অপশন a - এর 4 দ্বারা 43, 91 ও 183 কে ভাগ - করলে প্রতিক্ষেত্রেও অবশিষ্ট থাকে।"
A shopkeeper expects a gain of 22.5% on his cost price. If in a week, his sale was of Tk. 392, what was his profit ?
Correct Answer:
C: Tk. 72
Explanation:
A shopkeeper expects a gain of 22.5% on his cost price. If in a week, his sale was of Tk. 392, what was his profit ? Correct Answer Tk. 72 ধরি, ক্রয়মূল্য x টাকা x + x × 2.25/100 = 392 1.225x = 392 x = 392/1.225 = 392 ×1000 /1225 x = 320 লাভ = 392 - 320 = 72 টাকা
If doubling a number and adding 20 to the result gives the same answer as multiplying the number by 8 and taking away 4 from the product, the number is :
Correct Answer:
C: 4
Explanation:
If doubling a number and adding 20 to the result gives the same answer as multiplying the number by 8 and taking away 4 from the product, the number is : Correct Answer 4 "ধরি, সংখ্যাটি x তাহলে, 2x + 20 = 8x – 4 ⇒ 8x – 4 = 2x + 20 ⇒ 8x – 2x = 20 + 4 ⇒6x = 24 ∴ x = 4"
The sum of three consecutive multiples of 3 is 72. What is the largest number?
Correct Answer:
C: 27
Explanation:
The sum of three consecutive multiples of 3 is 72. What is the largest number? Correct Answer 27 "ধরি, সবচেয়ে ছোট গুণিতকটি 3x ∴ পরের ২য় ,, 3(x + 1) ∴ পরের ৩য় ,, 3(x + 2) প্রশ্নমতে, 3x + 3 (x + 1) + 3 (x + 2) = 72 ⇒ 3x + 3x + 3 + 3x + 6 = 72 ⇒ 9x + 9 = 72 ⇒ 9x = 72 – 9 ⇒ x = = 7 অর্থাৎ ছোট গুণিতকটি 7 ∴ সবচেয়ে বড় গুণিতকটি (multiple) 3(7 + 2) = 27"
The least whole number which when subtracted from both the terms of the ratio 6 : 7 gives a ratio less than 16:21 is :
Correct Answer:
B: 3
Explanation:
The least whole number which when subtracted from both the terms of the ratio 6 : 7 gives a ratio less than 16:21 is : Correct Answer 3 ধরি,ক্ষুদ্রতম সংখ্যা x বাদ দিলে ratio 16 : 21 এর সমান হয়। 6 - x / 7 - x = 16/21 112 - 16x = 126 - 21x 21x - 16x = 126 - 112 x = 14/5 x = 2.8 x এর মান যত বৃদ্ধি পাবে অনুপাত 16/21 এর চেয়ে তত ছোট হবে। ক্ষুদ্রতম পূর্ণ সংখ্যা x = 3
Rahim is 40 years old and Karim is 60 years old. How many years ago was the ratio of their ages 3 : 5?
Correct Answer:
B: 10 years
Explanation:
Rahim is 40 years old and Karim is 60 years old. How many years ago was the ratio of their ages 3 : 5? Correct Answer 10 years "ধরি, x বছর আগে তাদের বয়সের অনুপাত 3:5 ছিল। ∴ 40 – x : 60 - x = 3 : 5 বা, 40 - x60 - x = 35 বা, 5(40 – x) = 3 (60 – x) বা, 200 – 5x = 180 – 3x বা, 200 – 180 = 5x – 3x বা, 22 = 20 ∴ x = 10 অর্থাৎ 10 বছর আগে তাদের বয়সের অনুপাত 3 : 5 ছিল।"
Two taps A and B can fill a tank in 5 hours and 20 hours respectively. If both the taps are open then due to a leakage, it took 30 minutes more to fill the tank. If the tank is full, how long will it take for the leakage alone to empty the tank ?
Correct Answer:
D: 36 hrs
Explanation:
Two taps A and B can fill a tank in 5 hours and 20 hours respectively. If both the taps are open then due to a leakage, it took 30 minutes more to fill the tank. If the tank is full, how long will it take for the leakage alone to empty the tank ? Correct Answer 36 hrs A ও B একত্রে tank টি পূর্ন করে = 20×5/20×5 = 100/25 ঘন্টা = 4 ঘন্টা। Leakage সহ A ও B tank টি পূর্ণ করে ( 4 + 1/2) ঘন্টায় = 9/2 ঘন্টায় Leakage 1 ঘন্টায় খালি করে ( 1/4 - 2/9) অংশ = 9 - 8 /36 = 1/36 Leakage দ্বারা tank টি খালি হয়. 36 ঘন্টায়
A person was asked to state his age in years. His reply was, 'Take my age three years hence, multiply it by 3 and then subtract three times my age three years ago and you will know how old I am' What was the age of the person ?
Correct Answer:
A: 18 years
Explanation:
A person was asked to state his age in years. His reply was, 'Take my age three years hence, multiply it by 3 and then subtract three times my age three years ago and you will know how old I am' What was the age of the person ? Correct Answer 18 years ধরি, লেকটির বয়স x বছর প্রশ্নমতে লোকটির বয়স = ( x + 3) × 3 - 3 ( x - 3) বছর = 3x + 9 - 3x + 9 = 18 বছর
1/2 is what percent of 1/3?
Correct Answer:
B: 150%
Explanation:
1/2 is what percent of 1/3? Correct Answer 150% "ধরি, 13 এর x% = 12 বা, 13 × x100 = 12 বা, x = 3 × 1002 ∴ x = 150 ∴ 13 এর 150% এর মান 12
A train can travel 50% faster than a car. Both start lost about 12.5 minutes while stopping at the stations. The speed of the car is :
Correct Answer:
C: 120kmph
Explanation:
A train can travel 50% faster than a car. Both start lost about 12.5 minutes while stopping at the stations. The speed of the car is : Correct Answer 120kmph ধরি, গাড়ির গতিবেগ x কিমি / ঘন্টা ট্রেনের গাড়ির ( x + x × 500/100) = 3x/2 ঘন্টা 75x/x - 75/3x/2 = 12.5/60 75/x - 150/3x = 125/600 225 - 150 /3x = 125/600 125 × 3x = 600 × 75 x = 600 × 75 /125 × 3 x = 120
10 man, working 6 hours a day can complete a work in 18 days. How many hours a day must 15 men work to complete the same work in 12 days ?
Correct Answer:
A: 6
Explanation:
10 man, working 6 hours a day can complete a work in 18 days. How many hours a day must 15 men work to complete the same work in 12 days ? Correct Answer 6 M1 × T1 / H1 = M2 × T2 /H2 10 × 18 /6 = 15 × 12 /H2 H2 = 15 × 12 / 10 × 3 H2 = 6
A towel, when bleached, was found to have lost 20% of its length and 10% of its breadth. The percentage of decrease in area is :
Correct Answer:
D: 28%
Explanation:
A towel, when bleached, was found to have lost 20% of its length and 10% of its breadth. The percentage of decrease in area is : Correct Answer 28% ধরি, towel এর দৈর্ঘ x এবং towel এর প্রস্থ y Towel এর দৈর্ঘ কমে হয় ( x - 20x/100) = 4x/5 একক Towel এর প্রস্থ কমে হয় ( y - 10y/100) = 9y/10 একক ক্ষেত্রফল = 4x/4 × 9y/10 বর্গ একক = 18xy/25 বর্গ একক ক্ষেত্রফল হ্রাসের হার = ( xy - 18xy/35/ xy × 100) % = 28%
Which one of the following numbers is exactly divisible by 11?
Correct Answer:
D: 415624
Explanation:
Which one of the following numbers is exactly divisible by 11? Correct Answer 415624 "কোনো সংখ্যার জোড় স্থানীয় অঙ্কগুলোর সমষ্টি থেকে বাকি অঙ্কগুলোর সমষ্টি বিয়োগ করলে বিয়োগফল যদি শূন্য হয় তবে ঐ সংখ্যাটি 11 দ্বারা বিভাজ্য হবে। Option (d) - এর 415624 সংখ্যাটির জোড় স্থানীয় অঙ্কগুলোর সমষ্টি 1 + 6 + 4 বা 11 । বাকি অঙ্কগুলোর সমষ্টি 4 + 5 + 2 = 11 । এদের বিয়োগফল 11 – 11 = 0। সুতরাং (d) 415624 - ই সঠিক উত্তর।"
A man buys an article for 10% less than its value and sells it for 10% more than its value. His gain of loss percent is :
Correct Answer:
D: more than 20% profit
Explanation:
A man buys an article for 10% less than its value and sells it for 10% more than its value. His gain of loss percent is : Correct Answer more than 20% profit "ধরি, দ্রব্যটির প্রকৃত মূল্য 100 টাকা ∴ঐ ব্যক্তি দ্রব্যটি ক্রয় করেছে (100 – 10) বা 90 টাকায় আবার, ,, ,, বিক্রয় ,, (100 + 10) বা 110 টাকায় তাহলে, তার লাভ হলো (110 – 90) বা 20 টাকা এখন, ৩০ টাকায় লাভ হয় 20 টাকা ∴1 ,, ,, ,, 2090 ,, ∴ 100 ,, ,, ,, = 20 × 10090 = 22.22 টাকা ∴ Profit more than 20% ।"
A and B started a business jointly. A's investment was thrice the investment of B and the period of his investment was two times the period of investment of B. If B received Tk. 4000 as profit, then their total profit is :
Correct Answer:
D: Tk. 28,000
Explanation:
A and B started a business jointly. A's investment was thrice the investment of B and the period of his investment was two times the period of investment of B. If B received Tk. 4000 as profit, then their total profit is : Correct Answer Tk. 28,000 "ধরি, B - এর মূলধন x টাকা ∴ A ,, ,, 3x ,, ∴ তাদের মুনাফা বণ্টনের অনুপাত 3x : x = 3:1 আবার, A - এর সময় B - এর সময়ের দ্বিগুণ। ∴ সেক্ষেত্রে মুনাফার পুনঃবণ্টন অনুপাত 3 × 2 : 1 = 6:1 অনুপাতের রাশিদ্বয়ের সমষ্টি (6 + 1) বা 7। অর্থাৎ B - এর মুনাফা (profit) 1 টাকা হলে মোট মুনাফা 7 টাকা। ∴ B - এর ,, 4000 ,, ,, ,, , 4000 7 = 28000 টাকা"
A and B can do a piece of work in 5 days; B and C can do it in 7 days; A and C can do it in 4 days. Who among these will take the least time if put to do it alone?
Correct Answer:
A: A
Explanation:
A and B can do a piece of work in 5 days; B and C can do it in 7 days; A and C can do it in 4 days. Who among these will take the least time if put to do it alone? Correct Answer A "A + B = 5 B + C = 7 ∴ C > A অর্থাৎ A এর চেয়ে C এর বেশি সময় লাগে আবার, A + C = 4 A + B = 5 ∴ B > C ∴ B > C > A অর্থাৎ কাজটি করতে A সবচেয়ে কম (least) সময় নিবে।"
49×49×49×49=7?
Correct Answer:
C: 8
Explanation:
49×49×49×49=7? Correct Answer 8 "49 × 49 × 49 × 49 × = 72 × 72 × 72 × ; 72 = 7 2 + 2 + 2 + 2 = 72 ∴ 7? 78 ∴ ? = 8"
The simple interest on a certain sum of money at the rate of 5% p.a. for 8 years is Tk. 840. At what rate of interest the same amount of interest can be received on the same sum after 5 years?
Correct Answer:
B: 8%
Explanation:
The simple interest on a certain sum of money at the rate of 5% p.a. for 8 years is Tk. 840. At what rate of interest the same amount of interest can be received on the same sum after 5 years? Correct Answer 8% "প্রথম ক্ষেত্রে, 840 = P × 8 × 5100 [ ∵ I = pnr] বা, P = 840 × 1008 × 4 = 105 × 20 ∴ P = 2100 অর্থাৎ আসল 2100 টাকা দ্বিতীয় ক্ষেত্রে, 840 = 2100 × 5 × r ⇒ r = 8402100 × 5 × 100% = 8%
After deducting a commission of 5%, a T.V set costs Tk. 9595. Its marked price is :
Correct Answer:
C: Tk. 10,100
Explanation:
After deducting a commission of 5%, a T.V set costs Tk. 9595. Its marked price is : Correct Answer Tk. 10,100 "5% কমিশনের পর, বিক্রয়মূল্য (100 – 5) বা 95 টাকা হলে বাজারমূল্য 100 টাকা ∴ ,, 1 ,, ,, ,, 10095 ,, ∴ ,, 9595 ,, ,, ,, 100 × 959595 = 10,100 টাকা"
A merchant has 1000 kg of sugar, part of which he sells at 8% profit and the rest at 18% profit. He gains 14% on the whole. The quantity sold at 18% profit is :
Correct Answer:
C: 600 kg
Explanation:
A merchant has 1000 kg of sugar, part of which he sells at 8% profit and the rest at 18% profit. He gains 14% on the whole. The quantity sold at 18% profit is : Correct Answer 600 kg ধরি, x কেজিতে 8% লাভ করে ∴ (1000 - x) " 18% " "∴ 8100×(1000 - x)×18100 = 1000×14100⇒8x + 10(1000 - x) = 1000×14⇒8x + 18000 - 18x = 14000⇒ - 10x = 14000 - 18000⇒10x = 4000∴ x = 400 18% লাভে বিক্রি করে (1000 - 400) বা 600 কেজি।
In a dairy farm, 40 cows eat 40 bags of husk in 40 days. In how many days one cow will eat one bag of husk?
Correct Answer:
C: 40
Explanation:
In a dairy farm, 40 cows eat 40 bags of husk in 40 days. In how many days one cow will eat one bag of husk? Correct Answer 40 "40টি গরু 40 ব্যাগ ভুসি খায় 40 দিনে ∴ 1 ,, ,, 40 ,, ,, ,, 40 × 40 ∴ 1 ,, ,, 1 ,, ,, 40 × 4040 = 40 ,,"