PSLE Linda spent $480 in August. This amount was a 40% decrease from what she spent in July. The amount she spent in September was a 15% 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 |
- 40% |
|
August |
60% |
100 u |
Change |
|
+ 15 u |
September |
|
115 u |
(a)
Spending in July = 100%
Spending in August = 100% - 40% = 60%
60% = 480
1% = 480 ÷ 60 = 8
Spending in July
= 100%
= 100 x 8
= $800
Spending in August = 100 u
Spending in September = 100 u + 15 u = 115 u
100 u = 480
1 u = 480 ÷ 100 = 4.8
Spending in September
= 115 u
= 115 x 4.8
= $552
Total spending from July to September
= 800 + 480 + 552
= $1832
(b)
Decrease in spending in September compared to July
= 800 - 552
= $248
Percentage decrease
=
Decrease in spendingSpending in July x 100%
=
248800 x 100%
= 31%
Answer(s): (a) $1832; (b) 31%