Mr Pierre is 2 times as old as his son, Daniel. 20 years ago, the ratio in the age of Mr Pierre and Daniel was 9 : 2. Find Mr Pierre's current age.
| |
Mr Pierre |
Daniel |
Difference |
| Before |
9x1 =
9 u |
2x1 =
2 u |
7x1 =
7 u |
| Change |
+ 20 |
+ 20 |
|
| After |
2x7 =
14 u |
1x7 =
7 u |
1x7 =
7 u |
The difference in the age of Mr Pierre and Daniel 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 Daniel is the same.
Increase in Daniel's age
= 7 u - 2 u
= 5 u
5 u = 20
1 u = 20 ÷ 5 = 4
Mr Pierre's current age
= 14 u
= 14 x 4
= 56
Answer(s): 56
