Japheth's current age is 3 times as old as Michael's age years ago. Today, Michael's age is Japheth's age the same number of years ago. How old is Michael's age now if the total of their current age is 10?
| |
Japheth |
Michael |
Difference |
Total |
| Before |
1 p |
1 u |
1 p - 1 u |
|
| Change |
+ ? |
+ ? |
|
|
| After |
3 u |
1 p |
3 u - 1 p |
10 |
Total age of Japheth and Michael today = 3 u + 1 p
3 u + 1 p = 10 --- (1)
The difference in Japheth's age and Michael's age remains the same.
3 u - 1 p = 1 p - 1 u
3 u + 1 u = 1 p + 1 p
4 u = 2 p
2 u = 1 p
Substitute 1 p = 2 u into (1).
3 u + 1 p = 10
3 u + 2 u = 10
5 u = 10
1 u = 10 ÷ 5 = 2
Japheth's age now
= 10 - 3 u
= 10 - 3 x 2
= 10 - 6
= 4
Answer(s): 4
