PSLE Linda spent $160 in August. This amount was a 20% decrease from what she spent in July. The amount she spent in September was a 30% increase from what she spent in August.
- What was the total amount that Linda spent from July to September?
- What was the percentage increase in the amount Linda spent in September compared to July?
|
Spending |
July |
100% |
|
Change |
- 20% |
|
August |
80% |
100 u |
Change |
|
+ 30 u |
September |
|
130 u |
(a)
Spending in July = 100%
Spending in August = 100% - 20% = 80%
80% = 160
1% = 160 ÷ 80 = 2
Spending in July
= 100%
= 100 x 2
= $200
Spending in August = 100 u
Spending in September = 100 u + 30 u = 130 u
100 u = 160
1 u = 160 ÷ 100 = 1.6
Spending in September
= 130 u
= 130 x 1.6
= $208
Total spending from July to September
= 200 + 160 + 208
= $568
(b)
Increase in spending in September compared to July
= 208 - 200
= $8
Percentage increase
=
Increase in spendingSpending in July x 100%
=
8200 x 100%
= 4%
Answer(s): (a) $568; (b) 4%