A) 10 years
B) 20 years
D) 40 years
Five years ago ages of A and B are A – 5 , B – 5
So Averge , (A + B)/ 2 = 15
[(A – 5) + (B – 5)]/2 = 15
A + B – 10 = 30
A + B = 40 ……….(i)
Now average ages of A , B and C is 20
( A + B + C)/3 = 20
A + B + C = 60 ……… (ii)
Putting equation (i) into (ii)
40 + C = 60
C = 20
After 10 years C = 20 + 10 = 30
Related MCQs:
- Four years ago the average age of A, B and C was 25 years. Five years ago the average of B and C was 20 years. A’s present is:
- Five years ago the average age of p and Q was 15 years. Average age of P,Q and R today is 20 years. How did will R be after 10 years?
- Five years ago, the average age of A, B, C and D was 45 years with E joining them now, the average of all the five is 49 years. How old is E?
- The average age of A, B, C, D, and E is 40 years. The average age of A and B is 35 years and the average of C and D is 42 years. Age of E is?