PSLE Linda spent $840 in February. This amount was a 20% increase from what she spent in January. The amount she spent in March was a 25% decrease 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 |
+ 20% |
|
February |
120% |
100 u |
Change |
|
- 25 u |
March |
|
75 u |
(a)
Spending in January = 100%
Spending in February = 100% + 20% = 120%
120% = 840
1% = 840 ÷ 120 = 7
Spending in January
= 100%
= 100 x 7
= $700
Spending in February = 100 u
Spending in March = 100 u - 25 u = 75 u
100 u = 840
1 u = 840 ÷ 100 = 8.4
Spending in March
= 75 u
= 75 x 8.4
= $630
Total spending from January to March
= 700 + 840 + 630
= $2170
(b)
Decrease in spending in March compared to January
= 700 - 630
= $70
Percentage decrease
=
Decrease in spendingSpending in January x 100%
=
70700 x 100%
= 10%
Answer(s): (a) $2170; (b) 10%