Mr Pierre is 2 times as old as his cousin, Ethan. 25 years ago, the ratio in the age of Mr Pierre and Ethan was 9 : 2. Find Ethan's current age.
|
Mr Pierre |
Ethan |
Difference |
Before |
9x1 = 9 u |
2x1 = 2 u |
7x1 = 7 u |
Change |
+ 25 |
+ 25 |
|
After |
2x7 = 14 u |
1x7 = 7 u |
1x7 = 7 u |
The difference in the age of Mr Pierre and Ethan at first and in the end remains unchanged. Make the difference in age the same. LCM of 7 and 1 is 7.
The increase in the age of Mr Pierre and Ethan is the same.
Increase in Ethan's age
= 7 u - 2 u
= 5 u
5 u = 25
1 u = 25 ÷ 5 = 5
Ethan's current age
= 7 u
= 7 x 5
= 35
Answer(s): 35