PSLE Linda spent $240 in October. This amount was a 20% 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 decrease in the amount Linda spent in November compared to September?
|
Spending |
September |
100% |
|
Change |
+ 20% |
|
October |
120% |
100 u |
Change |
|
- 25 u |
November |
|
75 u |
(a)
Spending in September = 100%
Spending in October = 100% + 20% = 120%
120% = 240
1% = 240 ÷ 120 = 2
Spending in September
= 100%
= 100 x 2
= $200
Spending in October = 100 u
Spending in November = 100 u - 25 u = 75 u
100 u = 240
1 u = 240 ÷ 100 = 2.4
Spending in November
= 75 u
= 75 x 2.4
= $180
Total spending from September to November
= 200 + 240 + 180
= $620
(b)
Decrease in spending in November compared to September
= 200 - 180
= $20
Percentage decrease
=
Decrease in spendingSpending in September x 100%
=
20200 x 100%
= 10%
Answer(s): (a) $620; (b) 10%