Average Practice Questions

5 questions per page • Detailed step-by-step solutions

Question 16
Easy
The average monthly salary of 20 employees of a company is ₹24500. When the manager's salary is added, the average rises by ₹500. What is the manager's monthly salary?
A ₹34500
B ₹25000
C ₹35500
D ₹35000
Correct Answer: D

Explanation:

Step 1: Old total = 20 × ₹24500 = ₹490000. Step 2: New total = 21 × ₹25000 = ₹525000. Step 3: New member = ₹525000 − ₹490000 = ₹35000.
Question 17
Medium
The average of three numbers is 77. The first number is 4 times the second, and the second is 4 times the third. What is the smallest number?
A 44
B 11
C 176
D 22
Correct Answer: B

Explanation:

Step 1: Let the third number be t. Then the second = 4t and the first = 4 × 4t = 16t. Step 2: Sum = 16t + 4t + t = 21t = 3 × 77 = 231, so t = 11. Step 3: The numbers are 176, 44 and 11; the smallest is 11.
Question 18
Hard
A bowler's average was 22 runs per wicket. In his next match he took 7 wickets for 107 runs, which reduced his average by 1. How many wickets had he taken before this match?
A 40
B 47
C 45
D 35
Correct Answer: A

Explanation:

Step 1: Let n be the wickets before this match; runs conceded so far = 22n. Step 2: After the match: total runs = 22n + 107, wickets = n + 7, and the new average is 22 − 1 = 21, so 22n + 107 = 21(n + 7) = 21n + 147. Step 3: n = 147 − 107 = 40 → n = 40.
Question 19
Hard
The average age of a family of 7 members is 35 years. If the youngest member is 5 years old, what was the average age of the family just before the birth of the youngest member?
A 40 years
B 35 years
C 30 years
D 36 years
Correct Answer: B

Explanation:

Step 1: Present total age of the family = 7 × 35 = 245. Step 2: Just before the youngest was born (5 years ago), the youngest did not exist and each of the other 6 was 5 years younger: 245 − 5 − 6 × 5 = 210. Step 3: Average then = 210 ÷ 6 = 35 years.
Question 20
Medium
The average weight of 9 boys is 52 kg. When one boy leaves the group, the average weight decreases by 0.25 kg. What is the weight of the boy who left?
A 54.25 kg
B 50 kg
C 54 kg
D 52.25 kg
Correct Answer: C

Explanation:

Step 1: Total of all 9 = 9 × 52 = 468 kg. Step 2: After one leaves, 8 remain with average 52 − 0.25 = 51.75, so their total = 8 × 51.75 = 414 kg. Step 3: The one who left = 468 − 414 = 54 kg.