5 years ago, the average age of A, B and C was 25 years and 7 years ago, the average age of B and C was 20 years. What is A's present age? 5 वर्ष पहले A, B तथा C की औसत आयु 25 वर्ष थी एवं 7 वर्ष पहले B और C की औसत आयु 20 वर्ष थी। A की वर्तमान आयु क्या है?

5 years ago, average age of A,B,C was 25, so sum of their ages was 75. Present sum = 75 + 15 = 90. 7 years ago, average age of B,C was 20, so sum was 40. Present sum of B,C = 40 + 14 = 54. A's present age = 90 - 54 = 36 years. Option A (21) is too low, Option B (24) is 12 years short, and Option D (30) is 6 years short. Since 36 is not listed, Option E is correct.