PSLE Linda spent $300 in August. This amount was a 50% decrease from what she spent in July. The amount she spent in September was a 40% increase from what she spent in August.
- What was the total amount that Linda spent from July to September?
- What was the percentage decrease in the amount Linda spent in September compared to July?
|
Spending |
July |
100% |
|
Change |
- 50% |
|
August |
50% |
100 u |
Change |
|
+ 40 u |
September |
|
140 u |
(a)
Spending in July = 100%
Spending in August = 100% - 50% = 50%
50% = 300
1% = 300 ÷ 50 = 6
Spending in July
= 100%
= 100 x 6
= $600
Spending in August = 100 u
Spending in September = 100 u + 40 u = 140 u
100 u = 300
1 u = 300 ÷ 100 = 3
Spending in September
= 140 u
= 140 x 3
= $420
Total spending from July to September
= 600 + 300 + 420
= $1320
(b)
Decrease in spending in September compared to July
= 600 - 420
= $180
Percentage decrease
=
Decrease in spendingSpending in July x 100%
=
180600 x 100%
= 30%
Answer(s): (a) $1320; (b) 30%