PSLE Linda spent $375 in October. This amount was a 25% decrease from what she spent in September. The amount she spent in November was a 20% increase from what she spent in October.
- What was the total amount that Linda spent from September to November?
- What was the percentage decrease in the amount Linda spent in November compared to September?
|
Spending |
September |
100% |
|
Change |
- 25% |
|
October |
75% |
100 u |
Change |
|
+ 20 u |
November |
|
120 u |
(a)
Spending in September = 100%
Spending in October = 100% - 25% = 75%
75% = 375
1% = 375 ÷ 75 = 5
Spending in September
= 100%
= 100 x 5
= $500
Spending in October = 100 u
Spending in November = 100 u + 20 u = 120 u
100 u = 375
1 u = 375 ÷ 100 = 3.75
Spending in November
= 120 u
= 120 x 3.75
= $450
Total spending from September to November
= 500 + 375 + 450
= $1325
(b)
Decrease in spending in November compared to September
= 500 - 450
= $50
Percentage decrease
=
Decrease in spendingSpending in September x 100%
=
50500 x 100%
= 10%
Answer(s): (a) $1325; (b) 10%