Luis is 40 years older than his son. 5 years from now, his son will be
12 of his age while his nephew will be
38 of his son. Express his nephew’s present age as a fraction of Luis's present age. Leave your answer in its simplest form.
| |
Luis |
Luis's son |
Luis's nephew |
Difference between
Luis and Luis's son |
| Before |
16 u - 5 |
8 u - 5 |
3 u - 5 |
40 |
| Change |
+ 5 |
+ 5 |
+ 5 |
|
After
|
2x8 |
1x8 |
|
|
| |
8x1 |
3x1 |
|
Comparing Luis, his son and his nephew
in the end |
16 u |
8 u |
3 u |
8 u |
The repeated identity is the age of Luis's son. LCM of 1 and 8 is 8.
The difference in age between Luis and Luis's son remains unchanged.
Difference in age between Luis and Luis's son
= 16 u - 8 u
= 8 u
8 u = 40
1 u = 40 ÷ 8 = 5
His nephew's present age
= 3 u - 5
= 3 x 5 - 5
= 15 - 5
= 10
Luis's present age
= 16 u - 5
= 16 x 5 - 5
= 80 - 5
= 75
His nephew's present age as a fraction of Luis's present age
=
1075=
215 Answer(s):
215 
