Question

A is twice as old as B. Five years ago A was 3 times as old as B. Find their present ages.

Answer 1

Let age of B is x
Then age of A is 2x
5 years ago A is 3 times as old as B.
5 years ago the age of A was (2x-5)
Similarly 5 years ago age of B was( x-5)
According to the question, 2x-5=3(x-5)
2x-5=3x-15
x=10 yrs
So, present age of B is x i. e 10 yrs and present age of A is 2x=2×10=20 yrs

Answer 2

At present
A = 2B ………(1)

5 years ago
(A - 5) = 3 × (B - 5)
A - 5 = 3B - 15
A - 3B = -10
2B - 3B = -10 ………[∵ from (1) A = 2B]
B = 10

If B = 10 then from (1) A = 20

Present age of A = 20 years
Present age of B = 10 years