Question

Ten years later, A will be twice as old as B and five years ago, A was three times as old as B. What are the present ages of A and B?

Answer 1

$\huge\mathcal{\underline{Solution:-}}$

Call A and B the 2 present ages.

★ Ten years from now, A is twice as old as B

(A + 10) = 2(B + 10)................ (1)

★ Five years ago, A was 3 times as old as B

(A - 5) = 3(B - 5) .....................(2).

Solve the system (1) and (2).

From (2) --> A = 3B - 15 + 5 = 3B - 10.

★ Replace this value of A into (1) -->

3B - 10 + 10 = 2B + 20

B = 20

Present age of B is20.

_____________________________