Explanation:

A can do 3 piece of work in 4 hours, B and C together in 3 hours , and A and C together in 2 hours. How long will B alone take to do it? Correct Answer 12 hours A,B and C together need = (3×4)/(3 + 4) = 12/7 hours And C need 2 hours ∴B need = {(12/7)×2}/{2 - (12/7)} hours                   = (24/7)/{(14 - 12)/7}                   = 24/2 hours                   = 12 hours

Explanation:

A tank has two leakages. The first leakage alone can empty the tank in 9 minutes and the second alone would have done it in 6 minutes. If water leaks out at a constant rate. how long does it take both the leakage together to empty the tank ? Correct Answer 3.6 min দুটি বাদে সবগুলো rose দুটি বাদে সবগুলো tulip দুটি বাদে সবগুলো daisy স্পষ্ট বোঝা যাচ্ছে মোট ফুল তিনটি এবং প্রতি প্রকারের ফুল আছে ১টি করে।

Explanation:

The sum of the circumference of a circle and the perimeter of a rectangle is 130 cm. The area of the rectangle is 104 cm2 and the length of the rectangle is 13 cm. What is the area of the circle ? Correct Answer 616 cm2 3/4th of a minute এ minute এর কাঁটা খুব সামান্যই ঘুরবে।

Explanation:

A man riding his bicycle covers 150 metres 150 metres in 25 seconds. is his speed in km per hour? Correct Answer 25 ‘অভাবী - অভাব’ – এর লিঙ্গান্তর হয় না। তাই এটি অশুদ্ধ। তবে - ‘অভাগা - অভাগী’ শুদ্ধ লিঙ্গান্তর।

Explanation:

কোন দেশ প্রথম আণবিক বোমা ফেলা হয়? সঠিক উত্তর জাপান ১৯৪৫ সালের ৬ আগস্ট জাপানের হিরােশিমায়। বিশ্বের প্রথম আণবিক বােমা (লিটলবয়) ফেলা হয়। সেই বছরই ৯ আগস্ট জাপানের নাগাসাকি শহরে ফ্যাটম্যান নামে আরেকটি আণবিক বােমা ফেলা হয়।

Explanation:

A dishonest trader mixes 2 kg of vegetable ghee costing Tk. 45 a kg with 3 kg of standard ghee costing Tk. 70 per kg. He sells the mixed ghee at Tk. 65 per kg. what is his percentage of profit? Correct Answer 8.33% প্রশ্নে বলা হচ্ছে যে, 45 টাকা কেজি দরের 2 কেজি Vegetable ঘি'র সাথে 70 টাকা কেজি দরের 3 কেজি Standard ঘি'র সাথে Mix করে তা 65 টাকা কেজি দরে বিক্রয় করা হলো । শতকরা লাভের পরিমাণ কত ? 2 কেজি Vegetable ঘি'র ক্রয়মূল্য = 2 × 45 = 90 টাকা আবার, 3 কেজি Standard ঘি'র ক্রয়মূল্য = 3 × 70 = 210 টাকা (2 + 3) = 5 কেজি ঘি'র মোট ক্রয়মূল্য = 90 + 210 = 300 টাকা আবার, 5 কেজি ঘি'র বিক্রয়মূল্য = 5 × 65 = 325 টাকা লাভ হয় = (325−300300 × 100) = (25300 × 100) = 8.33%

Explanation:

Oranges are bought at 5 for Tk. 10 and sold at 6 for Tk. 15 . The gain percent is - Correct Answer 25% Cost per orange = (10/2) = 2 Tk Sell per orange = (15/6) = 2.5 Tk ∴gain percentage = {(2.5 - 2)/2}×100                               = 25%

Explanation:

A number,when 35 is subtracted from it, reduces to its 80 percent. What is four-fifth of that number ? Correct Answer 140 Let the number be x. Now, According to question x - 35 = 80% of x ⇒ x - 35 = 80x100 ⇒ x - 80x100 = 35 ⇒100x - 80x100 = 35 ⇒ 20x = 35×100 ⇒x = 35×10020 ⇒ x = 175 ⇒ ∴45x = 140

Explanation:

By selling an article for Tk. 100 a man gains Tk. 15 .Then, his gain % is - Correct Answer 15% Selling Price = 100 Tk, Gain = 15Tk ∴Cost Price = 100 - 15 = 85 Tk gain Percentage = (15/85)×100                               = 17(11/17)%

Explanation:

(0.04)2÷((0.008)×(0.2)6=(0.2)? Correct Answer None of these 0.04)2 ÷ 0.008×(0.2)6 = (0.2)x = > (0.0016/0.008)×(0.2)6 = (0.2)x = > (0.2)1 ×(0.2)6 = (0.2)x = > (0.2)7 = (0.2)x ∴x = 7

Explanation:

A man sold his watch at a loss of 5% . Had he sold it for Tk. 56.25 more he would have gained 10% . what was the cost on of the watch ? Correct Answer 375 He sold his watch at loss of 5%. If he sells his watch for Rs. 56.25 more, he would gain 10%. It means that15% = Tk. 56.25. So,1% = 56.2515 100% = 56.25 × 10015 = Tk. 375 Therefore, the cost price of the watch is Tk. 375

Explanation:

A student has to obtain 33% of the total marks to pass. He got 125 marks and failed by 40 marks. The maximum marks are : Correct Answer 500 Let the maximum marks be x. Then, 33% of x = 125 + 40 ⇒33100×× = 165 ⇒33x = 165×100 ⇒ x = 165×10033 ∴ x = 500

Explanation:

একটি বর্গাকার বাগানে ক্ষেত্রফল ১ হেক্টর। বাগানটির পরিসীমা কত মিটার? সঠিক উত্তর ৪০০ মি. ধরি, বাগানের দৈর্ঘ্য x মিটার " ক্ষেত্রফল x২ বর্গমিটার x২ = ১০০০০ [ ১ হেক্টর = ১০০০০ বর্গমিটার ] = > x = √১০০০০ x = ১০০ বাগানের পরিসীমা ৪x মিটার = (৪ × ১০০) " = ৪০০ মিটার

Explanation:

What percentage of numbers from 1 to 70 have squares that end in the digit 1 ? Correct Answer 20 Squares that end in the digit 1 be number of last digit 1 & 9. So numbers are 1, 9, 11, 21, 29, 31, 39, 41, 49, 51, 59, 61, 69. So total number is 14. ∴ Percentage = 1470×100 = 20

Explanation:

Half of 41 percent written as a decimal is Correct Answer 0.005 ‘ঝি’ – এর সমার্থক শব্দ হলো : সুতা, দুহিতা, তনয়া, মেয়ে, দুলালী, নন্দিনী, আত্মজা।

Explanation:

Evaluate 248+52+144 Correct Answer 16 ✓{248 + ✓(52 + ✓144)}     = ✓{ 248 + ✓(52 + 12)}   = ✓(248 + ✓64) = ✓(248 + 8) = ✓256 = 16

Explanation:

A sum of money at simple interest amounts to Tk. 815 in 3 tears and to Tk. 854 in 4 years.The sum is : Correct Answer Tk.698 Simple Internet ofr 1 year = Tk. (854 - 815) = Tk. 39 Simple Interest for 3 years  =  Tk. (39×3)  =  Tk. 117∴ Principal or sum  =  Tk. ( 815 - 117) Tk. 698

Explanation:

19.99×9.9+99.9=? Correct Answer 297.80 19.99×9.9 + 99.9 = 197.901 + 99.9 [ দশমিক ছাড়া গুণ করে পরে দশমিক বসাবেন] = 297.801

Explanation:

(0.75×4.4×2.4)÷0.6=? Correct Answer 13.2 (0.75×4.4×2.4)÷6 = (75×44×24×10)/(100×10×10×6) = 13.2

Explanation:

The average age of A,B,C,D and E is 40 years. The average age of A and B is 35 years and the average of C and D is 42 years. Age of E is - Correct Answer 46 A + B + C + D + E = 40 × 5 = 200 A + B = 35 × 2 = 70 C + D = 42 × 2 = 84 Therefore, E = (A + B + C + D + E) - (A + B + C + D) E = 200 - 70 - 84 E = 46 years

Explanation:

The cost price of an article is Tk. 7840. What should be the selling price of the article so that there is a profit of 7% Correct Answer Tk. 8388.80 100% = 7840 ∴107% = (7840×107)/100 = 8388.80

Explanation:

The simple interest on a sum of money at 8% per annum for 6 years is half the sum. The sum is : Correct Answer Data inadequate Let, principal amount be x So interest would be x2I = Pnr⇒x2 = x ×n×r⇒12 = n×r = .05×6 = .48 So, data inadequate

Explanation:

4 mat-weavers can weave 4 mats in 4 days. At the same rate, how many mats would be woven by 8 mat-weavers in 8 days? Correct Answer 16 Let the required number of bottles be x more weaves, more mats ( Direct Proportion), more days, more math (Direct Proportion) Weavers 44 88:: 4 : xDays∴4×4×x = 8×8×4⇒x  =  8×8×48×4∴x  = 16

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

Explanation:

36 men can complete a piece of work in 18 days. In how many days will 27 men complete the same work? Correct Answer 24 Let, the required number of days be x. Less man, More days ( Indirect Proportion) ∴27:36::18:x⇒2736 = 18x⇒27x = 18×36⇒x  =  18×3627∴x  = 24

Explanation:

The sum of the digits of two -digit number is 10, while when the digits are reversed , the number decrease by 54. Find the changed number . Correct Answer 28 Let the original number is 82 i.e 8 + 2 = 10 and when the digits are reversed i.e 28 The difference is 82 - 28 = 54 i.e, the number is decreased by 54.

Explanation:

Two numbers differ by 5. If their product is 336, then the sum of the two numbers is - Correct Answer 37 (x + y)² = (x - y)² + 4xy = 5² + 4×336 = 25 + 1344  = 1369 ∴(x + y) = 37

Explanation:

The selling price of an article after giving two successive discounts of 10% and 5% on the marked price is TK. 171 . What is the marked price ? Correct Answer Tk. 200 Equivalent Discount, = (A + B) - AB/100 = (10 + 5) - (10 × 5)/100 = 14.5% Let MP = X Now, X - 14.5% of X = 171(Selling Price) 0.855X = 171 X = 200 Hence, MP = Tk. 200 Going through options, 200(MP) = = 10%(disc.) ⇒ 180 = = 5%(disc.) ⇒ 171(CP)

Explanation:

If 7 spiders make 7 webs in 7 days, then 1 spider will make 1 web in how many days? Correct Answer 7 Let the required number days be x. Less spiders, More days (Indirect Proportion) Less webs, Less days (Direct Proportion) Spider 1 ; 7 Webs 7 : 1 ∴1×7×x = 7×1×7 ⇒x = 7

Explanation:

If x% of y is equal to z, What percent z is x ? Correct Answer 1002y x% of y = z ⇒x100y = z ∴x = z×100y

Explanation:

How much time will it take for an amount of Tk 450 to yield Tk. 81 as interest at 4.5% per annum of simple interest? Correct Answer 4 years n = (I×100)/(p×r)     = (81×100)/(450×4.5)     = 4 years

Explanation:

6×3(3-1) Correct Answer 36 6×3(3 - 1) = 6×3×2 = 36

Explanation:

There are n students in a school . If r% among the students are 12 years or younger, which of the following expressions represents the number of students who are solder than 12? Correct Answer n ( 100-r) /100 8 এর দুইগুণ 16, 16 এর দুইগুণ 32 একইভাবে 25 “ “ 50, 50 “ “ 100 হবে

Explanation:

A tank can be filled with water by two pipes A and B together in 36 minutes, the tank is filled in 40 minutes. The pipe B can alone fill the tank in - Correct Answer 90 munutes Let the pipes fill the tank in x minutes. Part of the tank filled by pipes A and B in one minute: 1/36 Part of the tank filled by pipe A in 1 minute = 1/36−1/x According to the question, 30 × (1/x) + (1/36−1/x) = 1 ⇒30x + 10/9−40/x = 1 ⇒10/x = 1/9 Hence, x = 90 minutes.

Explanation:

If 8 men can reap 801 hectares in 24 days, then dhow many hectares can 36 men reap in 30 days? Correct Answer 450 8 men in 24 days reap 80 hectares ∴1 men in 1 days reap 80/(8×24) hectares ∴36 men in 30 days reap (80×36×30)/(24×8) hectares = 450 hectares

Explanation:

If A and B together can complete a work in 18 days, A and C together in 12 day and B and C together in 9 days, then B alone can do the work in - Correct Answer 24 days A + B)’s 1 day’s work = 1/18 (B + C)’s 1 day’s work = 1/9 (C + A)’s 1 day’s work = 1/12 On adding all above equations, we get 2 (A + B + C)’s 1 day’s work = 1/18 + 1/9 + 1/12 = {2 + 4 + 3}/{36} = {9}/{36} = {1}/{4} ∴ (A + B + C)’s 1 day’s work = {1}/{8} Now, B’s 1 day’s work = (A + B + C)’s 1 day’s work – (A + C)’s 1 day’s work = {1}/{8} - {1}/{12} = {3 - 2}/{24} = {1}/{24} Hence B alone can do the work in 24 days. So option [B] is correct answer.

Explanation:

The ratio 5 :4 expressed as a percent equals Correct Answer 125% (5/4)×100 = 125%

Explanation:

In a 729 liters mixture of milk and water , the ratio of milk to water is 7:2 To get a new mixture containing milk and water in the ratio 7:3 the amount of water to be added is - Correct Answer 81 liters Quantity of milk in 729 litres of mixture = 7 × (729/9) = 567 litres, Quantity of water = 729 - 567 = 162 litres Let x litre of water be added to become ratio 7 : 3 Or, 7/3 = 567/(162 + x) Or, 162 × 7 + 7x = 567 × 3 Or, 7x = 1701 - 1134 = 567 Or, x = 567/7 = 81 litres water is to be added.

Explanation:

The average of 6 numbers is 7. The average of three numbers of them is 5. What will be the average of remaining numbers? Correct Answer 9 6 টি নাম্বার এর সমষ্টি ( 6×7) = 42 3 টি নাম্বার এর সমষ্টি ( 3 ×5) = 15  ( - ) বিয়োগ করে,     3 টি নাম্বার এর সমষ্টি = 27  Average = 27/3                 = 9