Adam receives his allowance of $300.
The ratio of Adam's spending to Adam's saving is 3 : 2.
The ratio of Adam's spending on food to the remaining of other expenses is 3 : 7.
- How much does Adam save?
- How much less does Adam spend on food than other expenses?
Spending |
Saving |
3 x 10 |
2 x 10 |
Food |
Other expenses |
|
3 x 3 |
7 x 3 |
|
9 u |
21 u |
20 u |
(a)
Adam's spending is the combined repeated identity.
Make the amount of spending the same using the LCM of 3 and 10.
LCM of 3 and 10 = 30
Total allowance
= 20 u + 30 u
= 50 u
50 u = 300
1 u = 300 ÷ 50 = 6
Amount that Adam saves
= 20 u
= 20 x 6
= $120
(b)
Amount that Adam spends less on food than other expenses
= 21 u - 9 u
= 12 u
= 12 x 6
= $72
Answer(s): (a) $120; (b) $72