Question

A father's age was 5 times his son's age 5 years ago and will be 3 times son's age after 2 years, the ratio of their present ages is equal to:option

Answer 1

let father's present age=x yrs
son's present age=y yrs
(x-5)=5(y-5)
x-5y=-20....(1)
(x+2)=3(y+2)
x-3y=4...(2)
from eq 1 & 2
-2y=-24
y=12
x=40 yrs

Answer 2

Answer:

10:3

Step-by-step explanation:

Let the present age of father is x and that of son is y.

5 years ago:-

Father's age = x-5

son's age = y-5

Therefore, from the first direction, we have

$(x-5)=5(y-5)\\\\x-5=5y-25\\\\x-5y=-20...(i)$

After 2 years:-

Father's age = x+2

son's age = y+2

Therefore, from the second direction, we have

$(x+2)=3(y+2)\\\\x+2=3y+6\\\\x-3y=4...(ii)$

Subtract equation (i) and (ii)

$-2y=-24\\\\y=12$

Substituting in (i)

$x-5(12)=-20\\\\x-60=-20\\\\x=40$

Hence, father's present age = 40 years

And son's present age = 12 years.

Ratio of their present age = 40/12 = 10/3= 10:3