PSLE Linda spent $1120 in August. This amount was a 40% increase from what she spent in July. The amount she spent in September was a 25% 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 |
+ 40% |
|
August |
140% |
100 u |
Change |
|
- 25 u |
September |
|
75 u |
(a)
Spending in July = 100%
Spending in August = 100% + 40% = 140%
140% = 1120
1% = 1120 ÷ 140 = 8
Spending in July
= 100%
= 100 x 8
= $800
Spending in August = 100 u
Spending in September = 100 u - 25 u = 75 u
100 u = 1120
1 u = 1120 ÷ 100 = 11.2
Spending in September
= 75 u
= 75 x 11.2
= $840
Total spending from July to September
= 800 + 1120 + 840
= $2760
(b)
Increase in spending in September compared to July
= 840 - 800
= $40
Percentage increase
=
Increase in spendingSpending in July x 100%
=
40800 x 100%
= 5%
Answer(s): (a) $2760; (b) 5%