PSLE Linda spent $400 in November. This amount was a 50% decrease from what she spent in October. The amount she spent in December was a 10% increase from what she spent in November.
- What was the total amount that Linda spent from October to December?
- What was the percentage decrease in the amount Linda spent in December compared to October?
|
Spending |
October |
100% |
|
Change |
- 50% |
|
November |
50% |
100 u |
Change |
|
+ 10 u |
December |
|
110 u |
(a)
Spending in October = 100%
Spending in November = 100% - 50% = 50%
50% = 400
1% = 400 ÷ 50 = 8
Spending in October
= 100%
= 100 x 8
= $800
Spending in November = 100 u
Spending in December = 100 u + 10 u = 110 u
100 u = 400
1 u = 400 ÷ 100 = 4
Spending in December
= 110 u
= 110 x 4
= $440
Total spending from October to December
= 800 + 400 + 440
= $1640
(b)
Decrease in spending in December compared to October
= 800 - 440
= $360
Percentage decrease
=
Decrease in spendingSpending in October x 100%
=
360800 x 100%
= 45%
Answer(s): (a) $1640; (b) 45%