Question

The ratio of the ages of Mona and Sona is 4:5. 12 years hence , their ages will be in the ratio of 5:6 , what will be Sona’s age after 6 years?

(A) 55 (B) 66 (C) 77 (D) 88​

Answer 1

Assumption:

Let:

• Sona's age = $4x$
• Mona's age = $5x$

Solution:

After 12 years:

$\implies{\frac{4x + 12}{5x + 12}}$ $= \frac{5}{6}$

$\implies{24x + 72 = 25x + 60}$

$\implies{25x - 24x = 72 - 60 }$

$\implies{x = 12}$

So, Sona's age = $5×12$

$= 60 \: yrs$

Sona's age after 6 years:-

$\implies{60 + 6}$

$\bold{\red{\implies{66 \: years}}}$

Hence, Option (B) is correct.

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