PSLE Linda saved $400 in October. This amount was a 20% decrease from what she saved in September. The amount she saved in November was a 15% increase from what she saved in October.
- What was the total amount that Linda saved from September to November?
- What was the percentage decrease in the amount Linda saved in November compared to September?
|
Savings |
September |
100% |
|
Change |
- 20% |
|
October |
80% |
100 u |
Change |
|
+ 15 u |
November |
|
115 u |
(a)
Savings in September = 100%
Savings in October = 100% - 20% = 80%
80% = 400
1% = 400 ÷ 80 = 5
Savings in September
= 100%
= 100 x 5
= $500
Savings in October = 100 u
Savings in November = 100 u + 15 u = 115 u
100 u = 400
1 u = 400 ÷ 100 = 4
Savings in November
= 115 u
= 115 x 4
= $460
Total savings from September to November
= 500 + 400 + 460
= $1360
(b)
Decrease in savings in November compared to September
= 500 - 460
= $40
Percentage decrease
=
Decrease in savingsSavings in September x 100%
=
40500 x 100%
= 8%
Answer(s): (a) $1360; (b) 8%