PSLE Linda spent $480 in August. This amount was a 20% 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 decrease in the amount Linda spent in September compared to July?
|
Spending |
July |
100% |
|
Change |
+ 20% |
|
August |
120% |
100 u |
Change |
|
- 20 u |
September |
|
80 u |
(a)
Spending in July = 100%
Spending in August = 100% + 20% = 120%
120% = 480
1% = 480 ÷ 120 = 4
Spending in July
= 100%
= 100 x 4
= $400
Spending in August = 100 u
Spending in September = 100 u - 20 u = 80 u
100 u = 480
1 u = 480 ÷ 100 = 4.8
Spending in September
= 80 u
= 80 x 4.8
= $384
Total spending from July to September
= 400 + 480 + 384
= $1264
(b)
Decrease in spending in September compared to July
= 400 - 384
= $16
Percentage decrease
=
Decrease in spendingSpending in July x 100%
=
16400 x 100%
= 4%
Answer(s): (a) $1264; (b) 4%