1. The average of first 10 even numbers is?

A. 37 B. 37.8 C. 39 D. 39.8

Answer: Option D
Explanation: Prime numbers between 30 and 50 are: 31, 37, 41, 43, 47 Average of prime numbers between 30 to 50 will be Average = [latex]\frac{31+37+41+43+47}{5}[/latex] = [latex]\frac{199}{5}[/latex] = 39.8
2. Reeya obtained 65, 67, 76, 82 and 85 out of 100 in different subjects, What will be the average.

A. 70 B. 75 C. 80 D. 85

Answer: Option B
Explanation: [latex]\frac{65+67+76+82+85}{5}[/latex] = 75
3. Find the sum of first 30 natural numbers

A. 470 B. 468 C. 465 D. 463

Answer: Option C
Explanation: Sum of n natural numbers Average = [latex]\frac{158 }{10}[/latex] = 15.8
4. The average of first 10 natural numbers is?

A. 5 B. 5.5 C. 6.5 D. 6

Answer: Option B
Explanation: Sum of 10 natural no. = [latex]\frac{n(n+1) }{2}[/latex] = 55 = [latex]\frac{30(30+1) }{2}[/latex] = [latex]\frac{30(31) }{2}[/latex] = 465
5. Find the average of first 10 multiples of 7

A. 35.5 B. 37.5 C. 38.5 D. 40.5

Answer: Option C
Explanation: Sum of 10 odd no. = 100 Average = [latex]\frac{100 }{10}[/latex] = 10

1. The average of first 10 prime numbers is?

A. 10 B. 12.5 C. 12.9 D. 15.5

Answer: Option C
Explanation: = [latex]\frac{7(1+2+3+...+10) }{10}[/latex] = [latex]\frac{7(10(10+1)) }{20}[/latex] [latex]\frac{7(110) }{20}[/latex] = 38.5
2. The average of four consecutive odd numbers is 24. Find the largest number.

A. 25 B. 27 C. 29 D. 31

Answer: Option B
Explanation: Let the numbers are x, x+2, x+4, x+6, then [latex]\frac{4x+12)}{4}[/latex] = 24 [x + 3 = 24 =>x = 21
3. When a student weighing 45 kgs left a class, the average weight of the remaining 59 students increased by 200g. What is the average weight of the remaining 59 students

A. 55 B. 56 C. 57 D. 58

Answer: Option C
Explanation: Let the average weight of the 59 students be A. So the total weight of the 59 of them will be 59*A. The questions states that when the weight of this student who left is added, the total weight of the class = 59A + 45 When this student is also included, the average weight decreases by 0.2 kgs [latex]\frac{59A+45}{60}[/latex] = a - 0.2 59 A + 45 = 60 A - 12 45 + 12 = 60 A -59 A A = 57
4. A motorist travel to a place 150 km away at an avearge speed of 50 km/hr and returns ar 30 km/hr.His average speed for the whole jouney in km/hr is

A. 36.5 km/hr B. 37.5 km/hr C. 35.5 km/hr D. 34.5 km/hr

Answer: Option B
Explanation: Average speed will be 2xy(x+y) km/hr = {2(50)(30)}{50+30} km/hr = 37.5 km/hr
5. The average of six numbers is X and the average of three of these is Y.If the average of the remaining three is z, then

A. x = y + z B. 2x = y + z C. x = 2y + z E. x = y + 2z

Answer: Option B X =((3y+3z)/6) or 2X= y + z

1. The average age of husband, wife and their child 3 years ago was 27 years and that of wife and the child 5 years ago was 20 years. The present age of the husband is

A. 40 B. 35 C. 45 D. 55

Answer: Option A
Explanation: 23 + Sum of the present ages of husband, wife and child = (27 * 3 + 3 * 3) years = 90 years. Sum of the present ages of wife and child = (20 * 2 + 5 * 2) years = 50 years. Husband's present age = (90 - 50) years = 40 years
2. Average of 10 matches is 32, How many runs one should should score to increase his average by 4 runs.

A. 70 B. 76 C. 78 D. 80

Answer: Option B
Explanation: Average after 11 innings should be 36 So, Required score = (11 * 36) - (10 * 32) = 396 - 320 = 76
3. Average of five numbers is 27. If one number is excluded the average becomes 25. The excluded number is

A. 35 B. 45 C. 55 D. 65

Answer: Option A
Explanation: Number is (5*27) - (4*25) = 135-100 = 35
4. Average weight of 10 people increased by 1.5 kg when one person of 45 kg is replaced by a new man. Then weight of the new man is

A. 50 B. 55 C. 60 D. 65

Answer: Option C
Explanation: Total weight increased is 1.5 * 10 = 15. So weight of new person is 45+15 = 60
5. A batsman makes a score of 87 runs in the 17th match and thus increases his average by 3. Find his average after 17th match

A. 36 B. 37 C. 38 D. 39

Answer: Option D
Explanation: Let the average after 17th match is x then the average before 17th match is x-3 so, 16(x-3) + 87 = 17x => x = 87 - 48 = 39