PSLE Linda saved $1170 in August. This amount was a 30% increase from what she saved in July. The amount she saved in September was a 30% decrease from what she saved in August.
- What was the total amount that Linda saved from July to September?
- What was the percentage decrease in the amount Linda saved in September compared to July?
|
Savings |
July |
100% |
|
Change |
+ 30% |
|
August |
130% |
100 u |
Change |
|
- 30 u |
September |
|
70 u |
(a)
Savings in July = 100%
Savings in August = 100% + 30% = 130%
130% = 1170
1% = 1170 ÷ 130 = 9
Savings in July
= 100%
= 100 x 9
= $900
Savings in August = 100 u
Savings in September = 100 u - 30 u = 70 u
100 u = 1170
1 u = 1170 ÷ 100 = 11.7
Savings in September
= 70 u
= 70 x 11.7
= $819
Total savings from July to September
= 900 + 1170 + 819
= $2889
(b)
Decrease in savings in September compared to July
= 900 - 819
= $81
Percentage decrease
=
Decrease in savingsSavings in July x 100%
=
81900 x 100%
= 9%
Answer(s): (a) $2889; (b) 9%