Question

The age of sonu and monu are in the ratio 7:5 ten year hence, the ratio of then ages will be 9:7 find their present age

Answer 1

Hi mate
Here is Ur answer

let the ages of Sonu and monu be 7x
and 5x respectively
and after ten yrs there ages will be 9x and 7x respectively

according to question
(7x+10)/(5x+10) = 9x/7x
(7x+10)/(5x+10) = 9/7
7(7x+10) = 9(5x+10)
49x+70 = 45x +90
4x = 20 => x = 20/4 = 5 yrs
sonu's age = 7x = 7×5 = 35 yrs
monu's age = 5x = 5×5 = 25yrs

hope this helps

Answer 2

Let
age of sonu = 7x  years
age of monu = 5x  years

===============

After 10 years, 
age of sonu = (7x + 10) years
age of monu = (5x + 10) years

According to the question,

$\frac{7x + 10}{5x + 10} = \frac{9}{7}$

7(7x + 10) = 9(5x + 10)

49x + 70 = 45x + 90 

49x - 45x = 90- 70 

4x = 20 

x = 20/4 

x = 5 

==========================

Present age of sonu = 7x = 7(5) = 35 years

Present age of monu = 5x = 5(5) = 25 years


:-)