PSLE Linda spent $400 in February. This amount was a 50% decrease from what she spent in January. The amount she spent in March was a 20% increase from what she spent in February.
- What was the total amount that Linda spent from January to March?
- What was the percentage decrease in the amount Linda spent in March compared to January?
|
Spending |
January |
100% |
|
Change |
- 50% |
|
February |
50% |
100 u |
Change |
|
+ 20 u |
March |
|
120 u |
(a)
Spending in January = 100%
Spending in February = 100% - 50% = 50%
50% = 400
1% = 400 ÷ 50 = 8
Spending in January
= 100%
= 100 x 8
= $800
Spending in February = 100 u
Spending in March = 100 u + 20 u = 120 u
100 u = 400
1 u = 400 ÷ 100 = 4
Spending in March
= 120 u
= 120 x 4
= $480
Total spending from January to March
= 800 + 400 + 480
= $1680
(b)
Decrease in spending in March compared to January
= 800 - 480
= $320
Percentage decrease
=
Decrease in spendingSpending in January x 100%
=
320800 x 100%
= 40%
Answer(s): (a) $1680; (b) 40%