Question

The average if two numbers A and B is 20, that of B and C is 19 and of C and A is 21. What is the value of A?

• A. 24
• B. 22
• C. 20
• D. 18

Answer 1

Answer:

B. 22

(A + B) = 2×20 = 40 (B + C) = 2×19 = 38 (C + A) = 2×21 = 42 ⇒ 2(A+B+C) = 40 + 38 + 42 = 120 ⇒ (A+B+C) = 60 A = (A+B+C) - (B+C) = 60 - 38 = 22