PSLE Linda spent $560 in November. This amount was a 40% increase from what she spent in October. The amount she spent in December was a 20% decrease 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 |
+ 40% |
|
November |
140% |
100 u |
Change |
|
- 20 u |
December |
|
80 u |
(a)
Spending in October = 100%
Spending in November = 100% + 40% = 140%
140% = 560
1% = 560 ÷ 140 = 4
Spending in October
= 100%
= 100 x 4
= $400
Spending in November = 100 u
Spending in December = 100 u - 20 u = 80 u
100 u = 560
1 u = 560 ÷ 100 = 5.6
Spending in December
= 80 u
= 80 x 5.6
= $448
Total spending from October to December
= 400 + 560 + 448
= $1408
(b)
Increase in spending in December compared to October
= 448 - 400
= $48
Percentage increase
=
Increase in spendingSpending in October x 100%
=
48400 x 100%
= 12%
Answer(s): (a) $1408; (b) 12%