PSLE Linda spent $910 in August. This amount was a 30% increase from what she spent in July. The amount she spent in September was a 10% decrease 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 |
+ 30% |
|
August |
130% |
100 u |
Change |
|
- 10 u |
September |
|
90 u |
(a)
Spending in July = 100%
Spending in August = 100% + 30% = 130%
130% = 910
1% = 910 ÷ 130 = 7
Spending in July
= 100%
= 100 x 7
= $700
Spending in August = 100 u
Spending in September = 100 u - 10 u = 90 u
100 u = 910
1 u = 910 ÷ 100 = 9.1
Spending in September
= 90 u
= 90 x 9.1
= $819
Total spending from July to September
= 700 + 910 + 819
= $2429
(b)
Increase in spending in September compared to July
= 819 - 700
= $119
Percentage increase
=
Increase in spendingSpending in July x 100%
=
119700 x 100%
= 17%
Answer(s): (a) $2429; (b) 17%