PSLE Linda spent $680 in November. This amount was a 15% decrease from what she spent in October. The amount she spent in December was a 40% 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 |
- 15% |
|
November |
85% |
100 u |
Change |
|
+ 40 u |
December |
|
140 u |
(a)
Spending in October = 100%
Spending in November = 100% - 15% = 85%
85% = 680
1% = 680 ÷ 85 = 8
Spending in October
= 100%
= 100 x 8
= $800
Spending in November = 100 u
Spending in December = 100 u + 40 u = 140 u
100 u = 680
1 u = 680 ÷ 100 = 6.8
Spending in December
= 140 u
= 140 x 6.8
= $952
Total spending from October to December
= 800 + 680 + 952
= $2432
(b)
Increase in spending in December compared to October
= 952 - 800
= $152
Percentage increase
=
Increase in spendingSpending in October x 100%
=
152800 x 100%
= 19%
Answer(s): (a) $2432; (b) 19%