Question

After 5 years, the age of a father will be treble the age of his son while 5 years,ago he was 7 times as old as his son was. find their presents ages.​

Answer 1

hi vivek!!!

Solution:

let father's present age be x years and son's present age be y years.

now,

after five years,

father will be x+5 years and son would be y +5 years old.

according to the first condition,

x+5= 3(y+5)

x+5= 3y+15

x-3y= 15-5

x-3y= 10........(1)

also,

five years ago,

father was x-5 years and son was y-5 years old.

according to the second condition,

x-5=7(y-5)

x-5=7y-35

x-7y= -35+5

x-7y= -30......... (2)

now,

subtracting (2) from (1),

x-3y= 10

- x +7y= 30

4y= 40

y= 40/4= 10

therefore,

present age of son= y = 10 years,

substituting value of y in (1),

x-3y= 10

x-3(10) = 10

x-30= 10

x= 30+10

x= 40

hence,

father's present age = x= 40 years.

checking:

five years ago father's age was 7 times his son's age:

x-5= 7(y-5)

40-5= 7(10-5)

35= 7× 5

35= 35

also,

five years hence, father's age would be three times his son's age.

x+5= 3(y+5)

40+5= 3(10+5)

45= 3× 15

45= 45

hope this helps!! ❤☺✌.... thanks for asking!!!