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