Question

Today Sanjay is 20 years younger than his father. Ten years ago he was one-half as old as his father. How old will his father be 10 years hence ?
1. 40 years
2. 60 years
3. 50 years
4. 30 years

Answer 1

Let the present ages of Sanjay and his father be x and y respectively.
Today Sanjay is 20 years younger than his father.
∴ x=y−20
∴ x−y=−20
Ten years ago he was one-half as old as his father.
∴ x−10=
2
y−10
∴ 2x−y=10 .
Solving (1) and (2) we get,
x=30 and y=50
Age of father 10yrs hence will be 50+10=60 years

Answer 2

Answer:

1) 40 years

Step-by-step explanation:

let sanjays father age today be x and sanjays age be y:-

Sanjay age=x-20

y=x-20______(1)

According to question:-

y-10= 3/2(x-20-10)

=3/2(x-30)

y-10 =3x/2-45______(2)

using equation 1 in 2 we have:-

x-20-10=3x/2-45

x-30=3x/2-45

x-3x/2=30-45

-x/2=-15

-x=-30

X=30

hence his fathers age after 10 years will=x+10

=30+10 =40 yrs