Question

The ages of a&b 9:4 after seven years age will be 5:3 find present age

Answer 1

let the present ages of a&b be 9x and 4x.
after 7 years,
A's age=9x+7
B's age=4x+7
9x+7/4x+7=5/3
3(9x+7)=5(4x+7)
27x+21=20x+35
27x-20x=35-21
7x=14
x=2
present age of A=9x=9×2=18years
present age of B=4x=4×2=8years

Answer 2

present age of A's=9x and B's=4x
After seven years,A's age =9x+7
B's age=4x+7
therefore,
$\frac{9x + 7}{4x + 7} = \frac{5}{3}$
therefore, 3(9x+7)=5(4x+7)
=27x+21=20x+35
=7x. =14
so,x=14÷7=2
therefore, A's present age=9x=9×2=18
B's present age=4x=4×2=8