PSLE Linda spent $960 in August. This amount was a 20% 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 decrease in the amount Linda spent in September compared to July?
|
Spending |
July |
100% |
|
Change |
+ 20% |
|
August |
120% |
100 u |
Change |
|
- 25 u |
September |
|
75 u |
(a)
Spending in July = 100%
Spending in August = 100% + 20% = 120%
120% = 960
1% = 960 ÷ 120 = 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 = 960
1 u = 960 ÷ 100 = 9.6
Spending in September
= 75 u
= 75 x 9.6
= $720
Total spending from July to September
= 800 + 960 + 720
= $2480
(b)
Decrease in spending in September compared to July
= 800 - 720
= $80
Percentage decrease
=
Decrease in spendingSpending in July x 100%
=
80800 x 100%
= 10%
Answer(s): (a) $2480; (b) 10%