When Min was 46 years old, her daughter was 2 times her son's age. Min would be twice her daughter's age when her son was 28 years old. How old would Min be when her son was 17 years old?
|
Min |
Daughter |
Son |
Before |
46 |
2 u |
1 u |
Change |
+ ? |
+ ? |
+ ? |
After |
2 p |
1 p |
28 |
The difference in the ages between Min and her daughter remains unchanged.
Difference in Min's and her daughter's ages at first
46 - 2 u = 2 p - 1 p
46 - 2 u =
1 p --- (1)
The difference in the ages between her daughter and her son remains unchanged.
Difference in her daughter's and her son's ages at first
2 u - 1 u = 1 p - 28
1 u + 28 =
1 p --- (2)
Make p the same.
(1) = (2)
46 - 2 u = 1 u + 28
1 u + 2 u = 46 - 28
3 u = 18
1 u = 18 ÷ 3 = 6
Age difference between Min and her son
= 46 - 1 u
= 46 - 6
= 40
Min's age when her son was 17 years old
= 40 + 17
= 57
Answer(s): 57