PSLE Linda spent $720 in October. This amount was a 20% increase from what she spent in September. The amount she spent in November was a 40% 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 |
|
- 40 u |
November |
|
60 u |
(a)
Spending in September = 100%
Spending in October = 100% + 20% = 120%
120% = 720
1% = 720 ÷ 120 = 6
Spending in September
= 100%
= 100 x 6
= $600
Spending in October = 100 u
Spending in November = 100 u - 40 u = 60 u
100 u = 720
1 u = 720 ÷ 100 = 7.2
Spending in November
= 60 u
= 60 x 7.2
= $432
Total spending from September to November
= 600 + 720 + 432
= $1752
(b)
Decrease in spending in November compared to September
= 600 - 432
= $168
Percentage decrease
=
Decrease in spendingSpending in September x 100%
=
168600 x 100%
= 28%
Answer(s): (a) $1752; (b) 28%