Adam receives his allowance of $112.
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 3 : 4.
- How much does Adam save?
- How much more does Adam spend on other expenses than food?
Spending |
Saving |
3 x 7 |
1 x 7 |
Food |
Other expenses |
|
3 x 3 |
4 x 3 |
|
9 u |
12 u |
7 u |
(a)
Adam's spending is the combined repeated identity.
Make the amount of spending the same using the LCM of 3 and 7.
LCM of 3 and 7 = 21
Total allowance
= 7 u + 21 u
= 28 u
28 u = 112
1 u = 112 ÷ 28 = 4
Amount that Adam saves
= 7 u
= 7 x 4
= $28
(b)
Amount that Adam spends more on other expenses than food
= 12 u - 9 u
= 3 u
= 3 x 4
= $12
Answer(s): (a) $28; (b) $12