Question

Jason’s age is 1/4 of his fathers age. 28years later, Jason’s age will be 3/5 of his fathers age. How old was Jason’s father when Jason was born?

Answer 1

j = Jason’s present age

f = Father’s present age

j = f / 4

28 years later, Jason’s age will be j + 28 , father’s age will be f + 28

( j + 28 ) / ( f + 28 ) = 3 / 5

Replace j = f / 4 in this equation

( f / 4 + 28 ) / ( f + 28 ) = 3 ∙ ( f + 28 ) / 5

cross multiply

5 ( f / 4 + 28 ) = 3 ∙ ( f + 28 )

5 f / 4 + 5 ∙ 28 = 3 f + 3 ∙ 28

5 f / 4 + 140 = 3 f + 84

Subtract 84 to both sides

5 f / 4 + 140 - 84 = 3 f + 84 - 84

5 f / 4 + 56 = 3 f

Subtract 5 f / 4 to both sides

5 f / 4 + 56 - 5 f / 4 = 3 f - 5 f / 4

56 = 3 f - 5 f / 4

56 = 12 f / 4 - 5 f / 4

56 = 7 f / 4

56 ∙ 4 = 7 f

224 = 7 f

244 / 7 = f

32 = f

f = 32

Father’s present age = 32

j = f / 4 = 32 / 4 = 8

Jason’s present age = 8

f - j = 32 - 8 = 24

Father is 24 yrs older of Jason.

Jason’s father was 24 years old when Jason was born.

Answer 2

Jason is X years old.'
Jason's father is 4x years old.

28 years later:
Jason is x + 28.
Jason's father is 4x + 28.

(x + 28)/(4x + 28) = 3/5,
5(x+28) = 3(4x + 28),
5x + 140 = 12x + 84,
7x = 56,
X = 8
4x = 32,
32 - 8 = 24 yrs. = Jason's father's age when Jason was born.


(x/4+28)/(