PSLE Linda saved $990 in November. This amount was a 10% increase from what she saved in October. The amount she saved in December was a 20% decrease 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 |
+ 10% |
|
November |
110% |
100 u |
Change |
|
- 20 u |
December |
|
80 u |
(a)
Savings in October = 100%
Savings in November = 100% + 10% = 110%
110% = 990
1% = 990 ÷ 110 = 9
Savings in October
= 100%
= 100 x 9
= $900
Savings in November = 100 u
Savings in December = 100 u - 20 u = 80 u
100 u = 990
1 u = 990 ÷ 100 = 9.9
Savings in December
= 80 u
= 80 x 9.9
= $792
Total savings from October to December
= 900 + 990 + 792
= $2682
(b)
Decrease in savings in December compared to October
= 900 - 792
= $108
Percentage decrease
=
Decrease in savingsSavings in October x 100%
=
108900 x 100%
= 12%
Answer(s): (a) $2682; (b) 12%