Question

5 years ago a man was 7 times as old as his son. After 5 years he will be thrice as odl as his son. Find their present ages

Answer 1

let the present age of son be x

present age of man be y

before 5 years

(x-5)7=y-5

7x-35=y-5

7x-y=30 ..... (I)

after 5 years

(x+5) 3=y+5

3x+15=y+5

3x-y=-10 ....... (II)

subtract (II) from (I) we get,

4x=40

x=10

3×10-y=-10

y=40

present age of son is 10 years and father is 40 years