Oscar is 5 times as old as his brother. In 12 years' time, Oscar will be 6 years less than twice of his brother's age. How old was Oscar 2 years ago?
| |
Oscar |
Oscar's brother |
Difference |
| Before |
5 u |
1 u |
4 u |
| Change |
+ 12 |
+ 12 |
|
| After |
2 p - 6 |
1 p |
1 p - 6 |
Difference in their ages at first
= 5 u - 1 u
= 4 u
Difference in their ages in the end
= 2 p - 6 - 1 p
= 1 p - 6
The difference in their ages remains unchanged.
4 u = 1 p - 6
4 u + 6 =
1 p --- (1)
Age of Oscar's brother in 12 years' time
= 1 u + 12
1 u + 12 =
1 p --- (2)
(1) = (2)
4 u + 6 = 1 u + 12
4 u - 1 u = 12 - 6
3 u = 6
1 u = 6 ÷ 3 = 2
Oscar's current age
= 5 u
= 5 x 2
= 10
Oscar's age 2 years ago
= 10 - 2
= 8
Answer(s): 8
