PSLE Linda spent $840 in August. This amount was a 40% increase from what she spent in July. The amount she spent in September was a 20% 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 |
|
- 20 u |
September |
|
80 u |
(a)
Spending in July = 100%
Spending in August = 100% + 40% = 140%
140% = 840
1% = 840 ÷ 140 = 6
Spending in July
= 100%
= 100 x 6
= $600
Spending in August = 100 u
Spending in September = 100 u - 20 u = 80 u
100 u = 840
1 u = 840 ÷ 100 = 8.4
Spending in September
= 80 u
= 80 x 8.4
= $672
Total spending from July to September
= 600 + 840 + 672
= $2112
(b)
Increase in spending in September compared to July
= 672 - 600
= $72
Percentage increase
=
Increase in spendingSpending in July x 100%
=
72600 x 100%
= 12%
Answer(s): (a) $2112; (b) 12%