PSLE Linda spent $450 in November. This amount was a 25% 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 |
- 25% |
|
November |
75% |
100 u |
Change |
|
+ 40 u |
December |
|
140 u |
(a)
Spending in October = 100%
Spending in November = 100% - 25% = 75%
75% = 450
1% = 450 ÷ 75 = 6
Spending in October
= 100%
= 100 x 6
= $600
Spending in November = 100 u
Spending in December = 100 u + 40 u = 140 u
100 u = 450
1 u = 450 ÷ 100 = 4.5
Spending in December
= 140 u
= 140 x 4.5
= $630
Total spending from October to December
= 600 + 450 + 630
= $1680
(b)
Increase in spending in December compared to October
= 630 - 600
= $30
Percentage increase
=
Increase in spendingSpending in October x 100%
=
30600 x 100%
= 5%
Answer(s): (a) $1680; (b) 5%