Question

Rohit 21 years younger than his father.After 7 year,their age will be in ratio 3:4.Find their present age​

Answer 1

Answer:

Present age of father is 77 years and present age of Rohit is 56 years

Step-by-step explanation:

Given that Rohit is 21 years younger that his father.

Let present age of father be $x$ years

Thus, present age of Rohit $= x - 21$ years

After 7 years,

Age of father $= x +7$ years

Age of Rohit $= x - 21 +7 = x - 14$ years

Given the ratio of Rohit's and father's age after 7 years is 3 : 4

Thus, we have

$\frac{x - 14}{x + 7} = \frac{3}{4}\\\\4 \times (\,x - 14)\, = 3 \times (\,x + 7)\,\\\\4x - 56 = 3x + 21\\\\ 4x - 3x = 21 + 56\\\\ x = 77$

Thus,

Present age of father $=77$ years

Present age of Rohit $= 77 - 21 = 56$ years