W = 43 = present woman’s age
D = 15 = present daugter’s age
W - D = 43 - 15
W - D = 28
Add D to both sides
W = D + 28
Woman is 28 yrs older of daugter.
Woman will be twice older of daugter when:
W = 2 D
So:
W = 2 D
Replace W = D + 28 in this equation
D + 28 = 2 D
Subtract D to both sides
28 = D
D = 28
Woman will be twice older of daugter when daugter be 28 yrs old.
Present daugter’s age = 15
28 - 15 = 13
After 13 yrs woman will be twice older of her daughter.
Proof:
After 13 yrs woman will be 43 + 13 = 56 yrs old
Daughter will be 15 + 13 = 28 yrs old
56 / 28 = 2
A woman is 43 years old, and her daughter is 15 years old. How many years will it be before the woman’s age is just twice her daughter’s?
1 answer