PSLE Linda spent $420 in October. This amount was a 40% increase from what she spent in September. The amount she spent in November was a 25% decrease from what she spent in October.
- What was the total amount that Linda spent from September to November?
- What was the percentage increase in the amount Linda spent in November compared to September?
|
Spending |
September |
100% |
|
Change |
+ 40% |
|
October |
140% |
100 u |
Change |
|
- 25 u |
November |
|
75 u |
(a)
Spending in September = 100%
Spending in October = 100% + 40% = 140%
140% = 420
1% = 420 ÷ 140 = 3
Spending in September
= 100%
= 100 x 3
= $300
Spending in October = 100 u
Spending in November = 100 u - 25 u = 75 u
100 u = 420
1 u = 420 ÷ 100 = 4.2
Spending in November
= 75 u
= 75 x 4.2
= $315
Total spending from September to November
= 300 + 420 + 315
= $1035
(b)
Increase in spending in November compared to September
= 315 - 300
= $15
Percentage increase
=
Increase in spendingSpending in September x 100%
=
15300 x 100%
= 5%
Answer(s): (a) $1035; (b) 5%