PSLE Linda spent $420 in August. This amount was a 40% increase from what she spent in July. The amount she spent in September was a 30% 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 |
+ 40% |
|
August |
140% |
100 u |
Change |
|
- 30 u |
September |
|
70 u |
(a)
Spending in July = 100%
Spending in August = 100% + 40% = 140%
140% = 420
1% = 420 ÷ 140 = 3
Spending in July
= 100%
= 100 x 3
= $300
Spending in August = 100 u
Spending in September = 100 u - 30 u = 70 u
100 u = 420
1 u = 420 ÷ 100 = 4.2
Spending in September
= 70 u
= 70 x 4.2
= $294
Total spending from July to September
= 300 + 420 + 294
= $1014
(b)
Decrease in spending in September compared to July
= 300 - 294
= $6
Percentage decrease
=
Decrease in spendingSpending in July x 100%
=
6300 x 100%
= 2%
Answer(s): (a) $1014; (b) 2%