Question

Six uear ago a father was seven times as age of his son after six year he will be 3times as old his son determine their present age

Answer 1

Answer:

Father's present age is 48 years

Son's present age is 12 years

Step-by-step explanation:

Let "f" be present age of father

Let "s" be present age of son

Given:

Six years ago, father's age was 7 times age of son

=> (f - 6) = 7(s - 6)

Six years hence, father's age will be 3 times age of son

=> (f + 6) = 3(s + 6)

The two equations are:

f - 6 = 7s - 42               ..(i)

f + 6 = 3s + 18              ..(ii)

Subtracting (ii) from (i), we get:

-12 = 4s - 60

4s = 48

s = 48/4

s = 12

substituting "s" in (i), we get:

f - 6 = 7*12 - 42

f - 6 = 84 - 42

f - 6 = 42

f = 48

Present age of father = 48 years

Present age of son = 12 years

Verification:

SIx years ago: father = 42, son = 6 (seven times)

Six yeas hence; father = 54, son = 18 (three times)

Answer 2

Step-by-step explanation:

let the present age of father be x

the present age of son be y

6 years ago father's age was x - 6

6 years ago son's age was y - 6

father was 7 times the age of son

x - 6 = 7( y - 6)

x - 6 = 7y - 42

x - 7y = - 42 + 6

x - 7y = - 36 equ (1)

6 years later father's age will be = x + 6

6 years later son's age will be = y + 6

father will be 3 times the age of son

x + 6 = 3(y + 6)

x + 6 = 3y + 18

x - 3y = 18 - 6

x - 3y = 12 equ (2)

subtract (1) - (2)

x - 7y - (x - 3y) = - 36 - 12

x - 7y - x + 3y = - 48

- 4y = - 48

4y = 48

y = 48/4

y = 12

substitute y = 12 in equ (2)

x - 3y = 12

x - 3(12) = 12

x - 36 = 12

x = 12 + 36

x = 48

father's present age = 48 years

son's present age = 12 years

hope you get your answer