Question

Rohan was 4 times as old as his son 6 years ago. After 6 years Rohan will be twice asold as his son. What is son &39;s present a

Answer 1

Answer:

Let present age of Rohit=x years

Let his sons present age=y years

Therefore atq

x-8=4[y-8]

x-8=4y-32

x-4y=-32+8

x-4y=-24………….(1)

Now 8 years hence their ages will be

x+8=2[y+8]

x+8=2y+16

x-2y=16–8

x-2y=8……………(2)

Subtract (2) from (1)

x-4y=-24

_x-2y = _8

-2y=-32

y=16

Substitute value of y in eq (1)

x-4y=-24

x-4×16=-24

x-64 =-24

x=-24+64=40

.: x=40

Hence Rohits present age =40 years

and his son's present age=16 years

Check

Rohits age 8 years ago=40–8=32years

His son's age 8 years ago=16–8=8 years

8×4=32 therefore he was 4 times his son's age 8 years ago

Rohits age 8 years hence=40+8=48 years

His son's age 8 years hence=16+8=24 years

24×2=48 therefore he will be twice the age of his son 8 years hence.