PSLE Linda spent $450 in October. This amount was a 50% increase from what she spent in September. The amount she spent in November was a 20% decrease from what she spent in October.
- What was the total amount that Linda spent from September to November?
- What was the percentage increase in the amount Linda spent in November compared to September?
|
Spending |
September |
100% |
|
Change |
+ 50% |
|
October |
150% |
100 u |
Change |
|
- 20 u |
November |
|
80 u |
(a)
Spending in September = 100%
Spending in October = 100% + 50% = 150%
150% = 450
1% = 450 ÷ 150 = 3
Spending in September
= 100%
= 100 x 3
= $300
Spending in October = 100 u
Spending in November = 100 u - 20 u = 80 u
100 u = 450
1 u = 450 ÷ 100 = 4.5
Spending in November
= 80 u
= 80 x 4.5
= $360
Total spending from September to November
= 300 + 450 + 360
= $1110
(b)
Increase in spending in November compared to September
= 360 - 300
= $60
Percentage increase
=
Increase in spendingSpending in September x 100%
=
60300 x 100%
= 20%
Answer(s): (a) $1110; (b) 20%