Average- MCQ Questions and Answers

Read- Average: Basic Concepts, Formulas

21. If the average of m nos is a, and when x is added to the 111 numbers, the average of m+1 numbers is b, then x is equal to which of the following?

(a) ma+b

(b) (m+1)b – ma

(c) 2ma – mb

(d) b-a+ma

22. The monthly salary of a person was Rs 320 for each of the first three years. He next got an annual increment of Rs 40 per month for each of the following successive 12 years. His salary remained stationary till retirement when he found that his average monthly salary during his service period was Rs 694. Find the period of his service.

(a) 25

(b) 15

(c) 40

(d) 50

23. The average weight of 3 men A, B, C is 84 kg. Another man D joins the group and the average now becomes 80 kg. If another man E whose weight is 3 kg more than that of D replaces A, then the average weight of B, C, D, and E become 79 kg. The weight of A is?

(a) 70 kg

(b) 72 kg

(c) 75 kg

(d) 80 kg

24. A man lends Rs 1000 in four sums. If he gets 3% for Rs 200, 3.5% for Rs 400, and 5% for Rs 250. What percent must he get for the remainder, if his average interest is Rs 3.85 percent?

(a) 10%

(b) 4%

(c) 8%

(d) 6%

25. The average age of the committee of seven trustees is the same as it was five years ago, a younger man having been substituted for one of them. How much younger was he than the trustee whose place he took?

(a) 28 years

(b) 35 years

(c) 40 years

(d) 51 years