five years ago Mathur age was twice his daughters age. if the sum of their present ages is 100 years find there ages is 5 year ago.
Answers
answer :
let,
present age of Mathur = 'x' years
present age of Mathur's daughter = 'y' years
five years ago,
Mathur's age = (x-5) years
his daughter's age = (y-5) years
Mathur age was twice his daughter's age
Mathur age = 2×his daughter's age
(x-5) = 2×(y-5)
x-5 = 2y-10
x = 2y-10+5
x= 2y-5 ---------- ( 1 )
given that,
sum of their present ages = 100 years
x+y = 100
substitute equation 1 in the above equation
2y-5+y = 100
3y-5 = 100
3y = 100+5
y = 105/3
y = 35 ----------- ( 2 )
the present age of mathur's daughter = y
= 35 years
the present age of Mathur = x
= 2y-5 ( from eq ( 1 ) )
= 2(35)-5
= 70-5
= 65
the present age of Mathur = x
= 65 years
5 years ago,
Mathur age = (x-5) years
= 65-5
= 60 years
his daughter's age = (y-5) years
= 35-5
= 30 years
.