Adam spends $400 of his income and saves the rest.
When he increases his savings by 15%, his spending decreases by 10%
- How much is Adam's spending at first?
- How much is Adam's spending in the end?
- How much is Adam's income?
|
Savings |
Spending |
Before |
100% |
100 u |
Change |
+ 15% |
- 10 u |
After |
115% |
90 u |
(a)
15% of Adam's savings = 10% of Adam's spending
100% of Adam's savings = $400
1% of Adam's savings = 400 ÷ 100 = $4
15% of Adam's savings = 15 x 4 = $60
10 u of Adam's spending = $60
1 u of Adam's spending = 60 ÷ 10 = $6
100 u of Adam's spending = 100 x 6 = $600
Amount of Adam's spending at first
= 100 u
= $600
(b)
Amount of spending in the end
= 90 u
= 90 x 6
= $540
(c)
Adam's income
= 100% + 100 u
= 400 + 600
= $1000
Answer(s): (a) $600; (b) $540; (c) $1000