Question

The ages of father and son are in the ratio 7: 3. Five years ago sum of their ages is 50 years. Find the age of the son 5 years hence from now?​

Answer 1

Amswer:

70 Years.

Explanation:

Let the present ages of father and son be 7x and 3x.

After 10 years, their ages will be 7x+10 and 3x+10.

According to the question, we have

3x+10

7x+10

=

1

2

1(7x+10)=2(3x+10)

7x+10=6x+20

7x−6x=20−10

x=10

Then present age of father is 7x, i.e. 7×10=70 years.

Answer 2

Step-by-step explanation:

consider age of father = x years

age of son=y years

x/y=7/3

3x-7y=0. (1)

5 years ago,

(x-5)+(y-5)=50

x+y-10=50

x+y=60 (2)

multiply by 3 to equation (2),

3x+3y=180 (3)

subtract equation (1) from (3),

10y=180

y=180/10

y=18 years

put value of y in equation (2),

x+18=60

x=42 years

age of father =42 years

age of son =18 years

age of son after 5 years =18+5=23 years