Given:
The ratio of present ages of Sonu and Monu = 7:5
The ratio of their ages after 10 years = 9:7.
To find:
The present ages of Sonu and Monu.
Solution:
Let the present ages of Sonu and Monu are 7x and 5x respectively.
Their ages after 10 years are (7x+10) and (5x+10) respectively.
The ratio of their ages after 10 years = 9:7.
[tex]\dfrac{7x+10}{5x+10}=\dfrac{9}{7}[/tex]
[tex]7(7x+10)=9(5x+10)[/tex]
[tex]49x+70=45x+90[/tex]
[tex]49x-45x=90-70[/tex]
On further simplification, we get
[tex]4x=20[/tex]
[tex]x=\dfrac{20}{4}[/tex]
[tex]x=5[/tex]
Now,
Sonu's present age = [tex]7x[/tex]
= [tex]7(5)[/tex]
= [tex]35[/tex]
Monu's present age = [tex]5x[/tex]
= [tex]5(5)[/tex]
= [tex]25[/tex]
Therefore, the present ages of Sonu and Monu are 35 and 25 respectively.
