Adam receives his allowance of $120.
The ratio of Adam's spending to Adam's saving is 3 : 1.
The ratio of Adam's spending on food to the remaining of other expenses is 2 : 7.
- How much does Adam save?
- How much less does Adam spend on food than other expenses?
Spending |
Saving |
3 x 3 |
1 x 3 |
Food |
Other expenses |
|
2 x 1 |
7 x 1 |
|
2 u |
7 u |
3 u |
(a)
Adam's spending is the combined repeated identity.
Make the amount of spending the same using the LCM of 3 and 9.
LCM of 3 and 9 = 9
Total allowance
= 3 u + 9 u
= 12 u
12 u = 120
1 u = 120 ÷ 12 = 10
Amount that Adam saves
= 3 u
= 3 x 10
= $30
(b)
Amount that Adam spends less on food than other expenses
= 7 u - 2 u
= 5 u
= 5 x 10
= $50
Answer(s): (a) $30; (b) $50