PSLE Linda saved $320 in August. This amount was a 20% decrease from what she saved in July. The amount she saved in September was a 40% increase from what she saved in August.
- What was the total amount that Linda saved from July to September?
- What was the percentage increase in the amount Linda saved in September compared to July?
|
Savings |
July |
100% |
|
Change |
- 20% |
|
August |
80% |
100 u |
Change |
|
+ 40 u |
September |
|
140 u |
(a)
Savings in July = 100%
Savings in August = 100% - 20% = 80%
80% = 320
1% = 320 ÷ 80 = 4
Savings in July
= 100%
= 100 x 4
= $400
Savings in August = 100 u
Savings in September = 100 u + 40 u = 140 u
100 u = 320
1 u = 320 ÷ 100 = 3.2
Savings in September
= 140 u
= 140 x 3.2
= $448
Total savings from July to September
= 400 + 320 + 448
= $1168
(b)
Increase in savings in September compared to July
= 448 - 400
= $48
Percentage increase
=
Increase in savingsSavings in July x 100%
=
48400 x 100%
= 12%
Answer(s): (a) $1168; (b) 12%