Question 504603: shane is twice as old as his daughter in 42 years the ratio of thir ages will be 4:3 what is the daughter's current age? Found 2 solutions by josmiceli, Maths68:Answer by josmiceli(19441) (Show Source):
You can put this solution on YOUR website! Let = Shane's age now
Let = Daughter's age now
given:
(1)
(2)
----------------------
I have 2 equations and 2 unknowns, so
it should be solvable
Multiply both sides of (2) by
(2)
(2)
(2)
Substitute (1) into (2)
(2)
(2)
(2)
His Daughter's age is 21
check:
(2)
(2)
(2)
Multiply both sides by
(2)
(2)
(2)
Shane is twice as old as his daughter -OK
You can put this solution on YOUR website! Let
Present age of Shane = s
Present age of his daughter = d
Given
Shane is twice as old as his daughter
s=2d ............(1)
In 42 years means we have add 42 in the present ages of both
s+42=d+42
then
ratio of thir ages will be 4:3
4:3=s+42:d+42
4/3=s+42/d+42
4*(d+42)=3*(s+42)
4d+168=3s+126
4d=3s+126-168
4d=3s+126-168
4d=3s-42 .............(2)
Put the value of s from (1) to (2)
4d=3(2d)-42
4d=6d-42
4d-6d=-42
-2d=-42
Divide by -2 both sides of above equation
-2d/-2=-42/-2
d=21
Put the value of d in (1)
s=2d
s=2(21)
s=42
Shane is 42 and her daughter is 21 years old
