PSLE Linda spent $800 in November. This amount was a 20% decrease from what she spent in October. The amount she spent in December was a 35% increase from what she spent in November.
- What was the total amount that Linda spent from October to December?
- What was the percentage increase in the amount Linda spent in December compared to October?
|
Spending |
October |
100% |
|
Change |
- 20% |
|
November |
80% |
100 u |
Change |
|
+ 35 u |
December |
|
135 u |
(a)
Spending in October = 100%
Spending in November = 100% - 20% = 80%
80% = 800
1% = 800 ÷ 80 = 10
Spending in October
= 100%
= 100 x 10
= $1000
Spending in November = 100 u
Spending in December = 100 u + 35 u = 135 u
100 u = 800
1 u = 800 ÷ 100 = 8
Spending in December
= 135 u
= 135 x 8
= $1080
Total spending from October to December
= 1000 + 800 + 1080
= $2880
(b)
Increase in spending in December compared to October
= 1080 - 1000
= $80
Percentage increase
=
Increase in spendingSpending in October x 100%
=
801000 x 100%
= 8%
Answer(s): (a) $2880; (b) 8%