Question

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

Answer 1

Supposition:-

• let the age of B be (x) yrs
• let the age of A be (2x) yrs

According to the question:-

:$\implies$ $\sf 3(x-5) = 2x-5$

:$\implies$ $\sf 3x-15 = 2x-5$

:$\implies$ $\sf 3x-2x = -5+15$

:$\implies$ $\sf x = 10$

hence, age of B = 10 yrs and B = 2×10 = 20 yrs

__________________________

Tips:-

• in such type of questions, catch the words like "is, was, etc" they mean " = "

• the multiplication is always done is smaller quantities

__________________________

Answer 2

Given :-

• A is twice old as B. Five years ago A was 3 times as old as B.

To Find :-

• Their Present Ages

Solution :-

⟶ Let Present Age of B is x

⟶ Then Present Age of A will be 2x

According to the Question :

➞ 3 (x - 5) = 2x - 5

➞ 3x - 15 = 2x - 5

➞ 3x - 2x = - 5 + 15

➞ x = 10

________________

Therefore :

• Present age of A = 2x = 2 × 10 = 20years
• Present age of B = x = 10years

________________