Explanation:

The average of smallest and largest primes between 60 and 80 is - Correct Answer 70 60 ও 80 এর মধ্যে বৃহত্তম মৌলিক সংখ্যা 79 60 ও 80 এর মধ্যে বৃহত্তম মৌলিল সংখ্যা + 61 সংখ্যা দুটির সমষ্টি = 140 সংখ্যা দুটির গড় = 140/2 = 70

Explanation:

The average of first five prime numbers is - Correct Answer 5.6 First 5 prime number = 2, 3, 5, 7, 11<math xmlns = "http://www.w3.org/1998/Math/MathML"><mo>∴</mo></math> Their average = <math xmlns = "http://www.w3.org/1998/Math/MathML"><mfrac><mrow><mn>2</mn><mo> + </mo><mn>3</mn><mo> + </mo><mn>5</mn><mo> + </mo><mn>7</mn><mo> + </mo><mn>11</mn></mrow><mn>5</mn></mfrac></math> = 5.6

Explanation:

the average of 10 numbers is 7. what will be the new average if each of the numbers is multiplied by 8? Correct Answer 56 The sum is = <math xmlns = "http://www.w3.org/1998/Math/MathML"><mn>10</mn><mo>×</mo><mn>7</mn><mo> = </mo><mn>70</mn></math>New Sum is = <math xmlns = "http://www.w3.org/1998/Math/MathML"><mn>70</mn><mo>×</mo><mn>8</mn><mo> = </mo><mn>560</mn></math>and new average Sum is = <math xmlns = "http://www.w3.org/1998/Math/MathML"><mn>560</mn><mo>÷</mo><mn>10</mn><mo> = </mo><mn>56</mn></math>

Explanation:

The average of a, b, c is 6 and a-b = 4, ab = 21, what is the value of c ? Correct Answer 8 Here, a - b = 4 or, a = b + 4 - - - - - - (i) Again,  ab = 21 or,    (b + 4)b = 21 [from (i)] or, b2 + 4b - 21 = 0 or. b2 + 7b - 3b - 21 = 0 or, b(b + 7) - 3(b + 7) = 0 or, (b + 7) (b - 3) = 0 or, b - 3 = 0  [b ≠ - 7] So, b = 3. Now,  a + b + c = 6 x 3 or,   a + b + c = 18 or,   b + 4 + b + c = 18 [from(i)] or,  3 + 4 + 3 + c = 18 or,  c = 18 - 10 = 8

Explanation:

A truck dirver must complete a 180-mile trip in 4 housr. If his average speed is 50 miles per hour for first 3 hours , then how fast must he travel for the final hour ? Correct Answer 30 Distance travelled in the first 3 hours = 50 x 3 = 150 mile. Remaining distance to be covered in the final hour = 180 - 150 = 30 mile

Explanation:

If the average of four numbers K, 2k+3, 3k-5, and 5k+1 is 63. What is the value of k? Correct Answer 23 ATQ, [(k) + (2k + 3) + (3k - 5) + (5k + 1)]/4 = 63 = > 11k - 1 = 252 = > k = 253/11 = 23 ans: 23

Explanation:

The average of 7 numbers of 40. If 3 more numbers, with an average of 21, are added to these numbers, what will be the average of the combined 10 number? Correct Answer 34.3 The average of 7 numbers of 40. If 3 more numbers, with an average of 21, are added to these numbers, what will be the average of the combined 10 number? Total of 7 numbers = 7 x 40 = 280 Total of 3 numbers = 3 x 21 = 63 Total of (7 + 3 = 10) numbers  = 280 + 63 = 343 So, average = 343 / 10 = 34.3

Explanation:

In a class of 22 students, 21 students get an average of 44 marks . If the remaining students get 66 marks , the average marks of the whoe class is - Correct Answer 45 Total marks of the 21 students = 44 x 21 = 924 So, total marks of the whole class = 924 + 66 = 990 Average marks of the whole class = 990 / 22 = 45.

Explanation:

৬, ৮, ১০ এর গাণিতিক গড় , ৭, ৯, এবং নিম্নলিখিত অন্য কোন সংখ্যার গাণিতিক গড়ের সমান ? সঠিক উত্তর ৮ প্রশ্নমতে,৬+৮+১০৩=৭+৯+ক৩বা, ২৪ = ১৬ + কবা, ক = ৮

Explanation:

The average age of 6men, 8women and 1 young boy is 35 years. What is the age of the boy,if the average age of the men is 40 and that of the women is 34? Correct Answer 13 The total number of persons = 6 + 8 + 1 = 15 The total age of all of them = 15x35 = 525 The total age of 6 men = 6x40 = 240 The total age of 8 women = 8x34 = 272 Therefore, the age of the boy = 525 - (240 + 272) = 13

Explanation:

In a cricket match , five batsmen A, B, C, D and E scored an average of 36 runs. D scored 5 more than E, E scored 8 fewer than A, B scored as many as D and E combined, and B and C jointly scored 107. How many runs did E score? Correct Answer 20 A+B+C+D+E = 36*5 = 180D = E+5                E = A-8             B = D+E = E+5+E = 2E+5B+C = 107 or, C = 107-B = 107-2E-5 = 102-2EE+8+2E+5+102-2E+E+5+E = 1803E = 180-120E = 60 (Ans.)

Explanation:

Average age of three brothers is 16 years . Average age of these brothers along with their father is 25 years. What is the age of their father ? Correct Answer 52 Total age of the three brothers = 3 x 16 = 48 years Total age of the brothers along with their father = 4 x 25 = 100 So, age of the father = 100 - 48 = 52 years

Explanation:

If taka 45000 was invested in a share when the price per share was taka 90 and taka 3000 was invested when the price per share was taka 60, what was the average price per share purchased? Correct Answer 87.27 Average price = (45000 + 300o) /(500 + 50) = 87.27

Explanation:

If the average of 5, 9 ,M and n is 12 m what is the average of (m +7) and (n -3) ? Correct Answer 19 here,5+9+m+n4=12=>  m + n = 34   …………(i)and,Av of (m+7) and (n-3) = (m+7)+(n-3)2=m+n+42=34+42      …………………..  [m+n=34]= 19

Explanation:

The average age of 12 students is 20 years. If the age of one more student is included, the average decreases by 1, what is the age of the new student ? Correct Answer 7 Total age of 12 students = 12 x 20 = 240 years New average = 20 - 1 = 19 years Total age of (12 + 1 = 13) students = 13 x 19 = 247 So, age of the new student = 247 - 240 = 7 years

Explanation:

Amer is working in an insurance company as traveling salesman. He drove 373.5 miles on Monday, 481.6 miles on Tuesday, 392.8 miles on Wednesday, 502 miles on Thursday and 53.7 miles on Friday . What is his average traveling? Correct Answer 360.72 miles Total days = 5 Total driving = 373.5 + 481.6 + 392.8 + 502 + 53.7 = 1803.6 miles Average travelling = 1803.6 / 5 = 360.72 miles

Explanation:

A truck driver must complete a 180-mile trip in 4 hours. If his average speed is 50 miles per hour for the first 3 hours, then how fast must he travel for the final hour ? Correct Answer 30 50 × 3 = 150 180 - 150 = 30

Explanation:

The average of a a, b, c is 6 and a-b =4, ab = 21, What is the value of c ? Correct Answer 8 a + b + c = 6 ×3 = 18 ( a + b)2 = ( a - b) 2 + 4ab = 42 + 4 × 21 = 16 + 84 = 100 a + b = 10 10 + c = 18 c = 8

Explanation:

The average of 10 numbers is ---10. If the sum of 6 of them is 100, then what is the average of the other 4 numbers ? Correct Answer -50 Total of 10 numbers = - 10×10 = - 100 the sum of 6 numbers  is 100 so,Sum of last 4 numbers = - 100 - 100 = - 200 ∴Average = - 200/4 = - 50 (ans)

Explanation:

Salam's average in four test is 80%. What mark does she need to score in her fifth test to make her average 84%? Correct Answer 100% the sum of the first 4 test scores is 4*80 = 320.  the sum of ALL 5 scores to be 5*84 = 420.  ∴she need score in her fifth test = 420 - 320 = 100. (ans)

Explanation:

In an examination of four subjects, a student got 70,80, 90 and x marks and his average was 75. What was the value of x? Correct Answer 60 Here, 70 + 80 + 90 + x = 4 x 75 or,  x = 300 - 240 So,  x =  60

Explanation:

The average of 100 observations in a study was calculated as 49.7 . Later it was revealed that one of the observations was misread as 64 instead of 94. What will be the correct average ? Correct Answer 50 The erroneous total of the obsevations = 49.7 x 100 = 4970 The correct total of the observations = 4970 - 64 + 94 = 5000 So, the correct average = 5000/100 = 50.

Explanation:

A survey of City A found an average of 3.2 people per household and an average of 1.2 DVD players per household . If 48,000 people live in City A, how many DVD players are there in City A? Correct Answer 18,000 3.2 people live in 1 house hold 1 people live in 1/3.2 house hold 48000 people live in 48000/3.2 house hold = 15000 house hold 1 house hold contain 1.2 DVD 15000 house hold contain. = ( 1.2 ×15000) = 18, 000 house hold

Explanation:

50 men took a dip in a water tank 40m long and 20m broad on a religious day. If the average displacement of water by a man is 4 m3 , then the rise in the water level in the tank will be -- Correct Answer 25 cm Total volume of water displacement = 4×50 = 200m3 Rise of water level = 200/(40×20) m = . 25m = 25 cm

Explanation:

The average of 5 consecutive numbers is n. If the next two numbers are also included, the average will : Correct Answer increase by 1 ধরি, প্রথম সংখ্যাটি a তাহলে, ( a + a + 1 + a + 2 + a + 3 + a + 4)/5 = x (5a + 10)/5 = x a + 2 = x এখন পরের দুটি যোগ করলে, (7a + 21)/7 = a + 3 = a + 2 + 1 = x + 1 অর্থাৎ 1 increase হয়েছে।

Explanation:

If the sum of (8, 5 and x ) is 21, then the average of (8, 5 and x ) is - Correct Answer 7 According to question, 8 + 5 + x = 21or, x = 21 - 13so, x = 8So, the average is =8+5+83 or 213 or 7.

Explanation:

Razia spent 3 hours climbing 6 miles up a hill. She spent 2 hours coming down the hill in a different path which had a length of 8 miles. For Razia's completed climb up and down the hil , what was her average speed, in miles per hour? Correct Answer 2.8 Average speed = total distance / total time = (6 + 8) / (3 + 2) = 14/5 = 2.8 miles/hr

Explanation:

A man travels 100 miles at 20 miles per hour, 60 miles at 30 miles per hour and 80 miles at 10 miles per hour, what is his average rate for the three trips? Correct Answer 16 miles per hr Time travelled at 20 miles//hr = 100/20 = 5 hrs Time travelled at 30 miles//hr = 60/30 = 2 hrs Time travelled at 10 miles//hr = 80/10 = 8 hrs Total time travelled = 5 + 2 + 8 = 15 hrs Total travelled = 100 + 60 + 80 = 240 miles Average rate = 240 / 15 = 16 miles per hour

Explanation:

If the average of 5 consecutive integers is 12, find the smallest integer. Correct Answer 10 The third number is the average number of 5 consecutive integers. So, the smallest integer is = 12 - 2 = 10

Explanation:

If Tk. 45,000 was invested in a share when the price per share was Tk. 90 and Tk. 30,000 was invested when the price per share was Tk. 60, what was the average price per share purchased? Correct Answer Tk. 75 Total investment = 45000 + 30000 = 75000 Number of shares bought by at 90 TK rate = 45000/90 = 500 Number of shares bought at 60 TK rate = 30000/60 = 500 Total number of shares bought = 500 + 500 = 1000 Average share price = 75000/1000 = 75 TK

Explanation:

A truck driver must complete a 180-mile trip in 4 hours. If he averages 50 miles an hour for the first three hours of his trip, how fast must he travel in the final hour? Correct Answer 30 mph d = s x t = 50 x 3 = 150 now distance left = 180 - 150 = 30 thus he need s to travel 30 miles in 4th hour thus his speed should be 30 miles per hour

Explanation:

The average of three Numbers is U. If two numbers are x and y, which is the third number? Correct Answer 3 u - x - y ধরি, third number হচ্ছে z x + y + z3 = v⇒x + y + z = 3v⇒z = 3v - x - y

Explanation:

তিনটি সংখ্যার গড় ৬ এবং উক্ত তিনটি সংখ্যাসহ ৪টি সংখ্যার গড় ৮। চতুর্থ সংখ্যার ১/২ অংশ নির্ণয় কর। সঠিক উত্তর ৭ ৩টি সংখ্যার সমষ্টি = ৩×৬ = ১৮ ৪টি সংখ্যার সমষ্টি = ৪×৮ = ৩২ সুতরাং,  ৪র্থ সংখ্যাটি = ৩২ - ১৮ = ১৪ ৪র্থ সংখ্যার অর্ধেক = ১৪/২ = ৭

Explanation:

A roast was cooked for 4 hours. The internal temperature of the roast rose from 32০ C to 145০ C. What was the average rise in temperature? Correct Answer 28.25০ C/hr AVERAGE=145-324=28.250

Explanation:

If 8x+8y=64, what is the average of x and y? Correct Answer 4 x এবং y এর গড় অর্থাৎ (x + y)/2 এর মান বের করতে হবে ।    এখন, 8x + 8y = 64        = > 8 (x + y) = 64      = > 8(x + y)/16 = 64/16 [ 16 দ্বারা উভয় পক্ষকে ভাগ করে ]      = > (x + y)/2 = 4

Explanation:

A train travels at an average speed of 50 miles per hour for 2.5 hour, and then travels at an average speed of 70 miles per hour for 1.5 hours. How far did the train travel in the entire 4 hour? Correct Answer 230 miles The train travelled = 50×2.5 + 70×1.5 = 125 + 105 =  230 miles

Explanation:

The average of 50 numbers is 38. If two numbers namely 45 and 55 are discarded, the average of the remaining number is : Correct Answer 37.50 Average for 50 number is 38. The total is = 38×50 = 1900 The total of discarded number is = 45 + 55 = 100 Hence the total for 48 number is = 1900 - 100 = 1800 So, The new average is = 1800÷48 = 37.5 ans: 37.5

Explanation:

A cricketer has a certain average for 9 innings. In the 10th innings he scores 100 runs, thus increasing his average by 8 runs. His new average is : Correct Answer 28 Let, initial average = x So, total runs = 9x And total runs scored in 10 innings = 9x + 100 So, new average = (9x + 100)/10 Since average increase by 8 ATQ, x + 8 = (9x + 100)/10 10x + 80 = 9x + 100 x = 20 New average 20 + 8 = 28 (Ans)

Explanation:

Masud has twice as much money as Selim has and Selim has 50% more money than what Bashir has. If the average money with them is Tk. 110, then Masud has : Correct Answer 180 Let Bashir has = x tk Then selim has = 3x/2 tk Then Masud has = 3x tk Now ratio of Masud: Selim: Bashir = 6:3:2 They have total = 110 × 3 = 330 Taka Then Masud share is 6/11 × 330 = 180 tk

Explanation:

Reza's average in four tests is 80% . what marks does he need in his fifth test to raise his average to 84% . Correct Answer 100% ধরি, প্রথম 4টি exam এর যোগফল x এবং 5th exam এ পাওয়া marks y xy = 80x = 4x80and,x + y5 = 84So,Y = 5x84 - x অথাৎ 100%

Explanation:

the average age of 12 children is 20 years. If the age of one more child is added, the average decreased by 1. What is the age of child added later? Correct Answer 7 Average of 12 is 20 Total = 12 × 20 = 240 Let the age of one more is x So, total 240 + x Average of 13 is (240 + x)/13 ATQ (240 + x)/13 = 19 or, 240 + x = 13 × 19 or, 240 + x = 247 ∴ x = 7 (ans)

Explanation:

A man walks 30 minutes at an average speed of 3 miles/hour. He waits 10 minutes for a bus, which bring him back to his starting point at 3:15. If he began his walk at 2:25 the same afternoon, find the average speed of the bus? Correct Answer 9 mph Here,  2:25 pm to 3:15 pm = 50 minutes Time taken by bus = 50 - (30 + 10) = 10 minutes = 10/60 hour = 1/6 hour The man walked for = 30 minutes = 30/60 hour = 1/2 hour He walked = 3×1/2 = 3/2 miles So,  speed of the bus = 3/2 ÷ (1/6) = 9 miles per hour

Explanation:

15 students took a test that was scored from 0 to 100. If exactly 10 students scored 75 of more on the test, find the lowest possible value for the average of the scores of all 15 students. Correct Answer 50 Total score of 10 students if scored exactly 75 each = 10×75 = 750 Total score of 5 student if scored minimum or 0 = 0 Total score of 10 + 5 = 15 students = 750 + 0 = 750 Average of the 15 students = 750 / 15 = 50

Explanation:

If the average of 9 consecutive integers is 0, what is the average of the last 4 of these integers? Correct Answer 2.5 রক্ত দানের পর শারীরিকভাবে দুর্বল অনুভূত হতে পারে। আর ক্লান্তি বা ঘুম ঘুম ভাব আসে সাধারণত পরিশ্রম করার পর। সুতরাং অর্থ অনুযায়ী (b) - ই সঠিক উত্তর।

Explanation:

A train went 300 miles from City X to City Y at an average speed of 80 mph. At what speed did it travel on the way back if its average speed for the whole trip was 100 mph? Correct Answer 133.33 mph Average speed for same distance is given by (2×v1×v2)/(v1+v2)So, (2×80×v2)/80+v2=100160×v2=8000+100×v260×v2=80003×v2=400v2=400/3 =133.33 Ans : 133.33 mph

Explanation:

The average of 6 number is 9 , when one number is discarded the average of the remaining numbers becomes 7.2 . What is the discarded number? Correct Answer 18 Total of 6 number is 6×9 = 54 If 1 number is discarded then there are 5 numbers So, total of 5 number is 5×7.2 = 36 So the discarded number is = ( 54 - 36) = 18

Explanation:

The average of 6 numbers is 25. If 3 more numbers, with an average of 22 are added to these numbers, what will be the average of the combined 9 numbers? Correct Answer 24 Sum of 6 numbers are = 25*6 = 150Sum of 3 numbers are = 3*22 = 66Sum of 9 numbers are = 150+66 = 216Average of 9 numbers are = 216/9                                                   = 24 (Ans.)