Adam receives his allowance of $400.
The ratio of Adam's spending to Adam's saving is 7 : 3.
The ratio of Adam's spending on food to the remaining of other expenses is 1 : 4.
- How much does Adam save?
- How much less does Adam spend on food than other expenses?
Spending |
Saving |
7 x 5 |
3 x 5 |
Food |
Other expenses |
|
1 x 7 |
4 x 7 |
|
7 u |
28 u |
15 u |
(a)
Adam's spending is the combined repeated identity.
Make the amount of spending the same using the LCM of 7 and 5.
LCM of 7 and 5 = 35
Total allowance
= 15 u + 35 u
= 50 u
50 u = 400
1 u = 400 ÷ 50 = 8
Amount that Adam saves
= 15 u
= 15 x 8
= $120
(b)
Amount that Adam spends less on food than other expenses
= 28 u - 7 u
= 21 u
= 21 x 8
= $168
Answer(s): (a) $120; (b) $168