Question

The sum of present ages of three persons is 75 years. five years ago their ages were in the ratio 4 : 5 : 6. find their present ages.

Answer 1

ratio = 4:5:6

Their ages are:

$75 \times \frac{4}{4 + 5 + 6} = 75 \times \frac{4}{15} = 20$

$75 \times \frac{5}{4 + 5 + 6} = 75 \times \frac{5}{15} = 25$

$75 \times \frac{6}{4 + 5 + 6} = 75 \times \frac{6}{15} = 30$

Answer 2

so given that sum of ages of these guys is 75 .
let age be 'x'.
4x+5x+6x=75
15x=75
x=5
age of first = 20 (4*5)
age of second = 25
age of third = 30
this way is the easiest way ,if doubt or want answers of more questions plz ask