Question

5 years ago, grandfather's age was 13 times his
grandson's age at that time. After 5 years, his age
will be five times as the grandson's age. Find their
present ages.​

Answer 1

Answer:

18 will be his your grandfather's age

Answer 2

Answer:

Let the grandfathers age be x

Let the grandson's age be y

According to first situation

Let the grandfather's age before 5 years be =x-5

Let the grandson's age before 5 years be =y-5

• It is given that five years ago grandfather's age was 13 times of his grandson
• (x-5)=13(y-5)
• x-5=13y-65
• x-5+65=13y
• x+60=13y
• x=13y-60.......(1)

According to second situation

Let the grandfather's age be =x+5

Let the grandson's age be=y+5

• It is given that after 5 years grandfather's age will be 5 times of his grandson
• x+5=5(y+5)
• x+5=5y+25
• x+5-25=5y
• x-20=5y....(2)

Substitute equation (1)in equation (2)

13y-60-20=5y

13y-80=5y

13y-5y=80

8y=80

y=80/8

y=10

The grandson's age is 10

To find grandfather's age substitute y=10 in equation(1)

• x=13y-60
• x=13(10)-60
• x=130-60
• x=70

Hence, the grandfather's age is 70