Ahmad's current age is 7 times as old as Zeph's age years ago. Today, Zeph's age is Ahmad's age the same number of years ago. How old is Ahmad's age now if the total of their current age is 99?
| |
Ahmad |
Zeph |
Difference |
Total |
| Before |
1 p |
1 u |
1 p - 1 u |
|
| Change |
+ ? |
+ ? |
|
|
| After |
7 u |
1 p |
7 u - 1 p |
99 |
Total age of Ahmad and Zeph today = 7 u + 1 p
7 u + 1 p = 99 --- (1)
The difference in Ahmad's age and Zeph's age remains the same.
7 u - 1 p = 1 p - 1 u
7 u + 1 u = 1 p + 1 p
8 u = 2 p
4 u = 1 p
Substitute 1 p = 4 u into (1).
7 u + 1 p = 99
7 u + 4 u = 99
11 u = 99
1 u = 99 ÷ 11 = 9
Ahmad's age now
= 7 u
= 7 x 9
= 63
Answer(s): 63
