Ahmad's current age is 3 times as old as Henry's age years ago. Today, Henry's age is Ahmad's age the same number of years ago. How old is Henry's age now if the total of their current age is 30?
| |
Ahmad |
Henry |
Difference |
Total |
| Before |
1 p |
1 u |
1 p - 1 u |
|
| Change |
+ ? |
+ ? |
|
|
| After |
3 u |
1 p |
3 u - 1 p |
30 |
Total age of Ahmad and Henry today = 3 u + 1 p
3 u + 1 p = 30 --- (1)
The difference in Ahmad's age and Henry'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 = 30
3 u + 2 u = 30
5 u = 30
1 u = 30 ÷ 5 = 6
Ahmad's age now
= 30 - 3 u
= 30 - 3 x 6
= 30 - 18
= 12
Answer(s): 12
