Sam is 40 years older than his son. 4 years from now, his son will be
12 of his age while his cousin will be
25 of his son. Express his cousin’s present age as a fraction of Sam's present age. Leave your answer in its simplest form.
| |
Sam |
Sam's son |
Sam's cousin |
Difference between
Sam and Sam's son |
| Before |
10 u - 4 |
5 u - 4 |
2 u - 4 |
40 |
| Change |
+ 4 |
+ 4 |
+ 4 |
|
After
|
2x5 |
1x5 |
|
|
| |
5x1 |
2x1 |
|
Comparing Sam, his son and his cousin
in the end |
10 u |
5 u |
2 u |
5 u |
The repeated identity is the age of Sam's son. LCM of 1 and 5 is 5.
The difference in age between Sam and Sam's son remains unchanged.
Difference in age between Sam and Sam's son
= 10 u - 5 u
= 5 u
5 u = 40
1 u = 40 ÷ 5 = 8
His cousin's present age
= 2 u - 4
= 2 x 8 - 4
= 16 - 4
= 12
Sam's present age
= 10 u - 4
= 10 x 8 - 4
= 80 - 4
= 76
His cousin's present age as a fraction of Sam's present age
=
1276=
319 Answer(s):
319 
