Question

The ages of Sonu and Monu are in the ratio 7:5.10 years hence ,the ratio of their ages is 9:7.Find their present ages

Answer 1

Let the ratio of their present ages be 7x:5x
After 10 yrs their ages would be 
7x+10 : 5x+10 = 9:7
on solving
x =5
therefore Sonu's age = 7*5 = 35 yrs
               Monu's age = 5*5 = 25 yrs





Hope it helps...:)

Answer 2

Heya !!!

Let the age of Sonu and monu be X and Y year's.


According to question,


X : Y = 7:5


X/Y = 7/5


5X = 7Y----------(1)


After 10 years age of sonu = (X+10) years.

After 10 years age of monu = (Y+10) years.


According to question,


X+10 : Y + 10 = 9:7


X + 10/Y +10 = 9/7


7(X + 10) = 9(Y+10)

7X + 70 = 9Y + 90

7X - 9Y = 90 -70

7X - 9Y = 20---------(2)


From equation (1) we get,



5X = 7Y


X = (7Y/5)-----------(3)


Putting the value of X in equation (2)


7X - 9Y = 20


7 × (7Y/5) - 9Y = 20


49Y/5 - 9Y = 20


49Y - 45Y /5 = 20


4Y = 20 × 5

4Y = 100

Y = 100/4 = 25 years


Putting the value of Y in equation (3)


X = 7Y/5 => 7 × 25 /5 => 175/5

X = 35 years.


Present age of Sonu = X = 25 years


and,


Present age of monu = Y = 35 years.




HOPE IT WILL HELP YOU..... :-)