When Gem was 48 years old, her son was 3 times her daughter's age. Gem would be twice her son's age when her daughter was 38 years old. How old would Gem be when her daughter was 2 years old?
|
Gem |
Son |
Daughter |
Before |
48 |
3 u |
1 u |
Change |
+ ? |
+ ? |
+ ? |
After |
2 p |
1 p |
38 |
The difference in the ages between Gem and her son remains unchanged.
Difference in Gem's and her son's ages at first
48 - 3 u = 2 p - 1 p
48 - 3 u =
1 p --- (1)
The difference in the ages between her son and her daughter remains unchanged.
Difference in her son's and her daughter's ages at first
3 u - 1 u = 1 p - 38
2 u + 38 =
1 p --- (2)
Make p the same.
(1) = (2)
48 - 3 u = 2 u + 38
2 u + 3 u = 48 - 38
5 u = 10
1 u = 10 ÷ 5 = 2
Age difference between Gem and her daughter
= 48 - 1 u
= 48 - 2
= 46
Gem's age when her daughter was 2 years old
= 46 + 2
= 48
Answer(s): 48