Answers

2015-11-12T14:50:48+05:30
The ages of A and B are in ratio of 7:5, 10 year hence the ratio of their
ages will be 9:7, find their present ages
:
The easy way to do this is by using a "multiplier"
let x = the multiplier
then
7x = A's present age
and
5x = B's present age
:
Adding 10 yrs to their age produces a ratio of 9:7, there
 = 
0
2015-11-12T18:24:34+05:30
Change in the question : Ten years later the ratio of their ages is 9 : 7
Solution:
Given, the ratio of the present ages of Sonal and Manoj = 7 : 5
Let the age of Sonal be `7x` yrs
And the age of Manoj be `5x` yrs
Ten years later their ages will be   (7x + 10) and   (5x + 10)
Given the ratio of the ages after 10 years = 9:7
Assume the ages as 9x and 7x

7x + 10 + 5x + 10 = 9x + 7x 
12x - 16x = -20
-4x = -20
x = -20/-4
x = 5
Therefore the present age of Sonal = 7x = 7×5 = 35 years
And the present age of Manoj = 5x = 5×5 = 25 years
3 3 3