PSLE A company offered 80 lamps at 20% discount during a 7-day sale. The line graph shows the number of lamps left unsold at the end of each day.
- On which day was the most number of lamps sold? Give your answer in this format. (Eg Day 1)
- What percentage of the 80 lamps were sold in the first four days of the sale?
- During the sale, the discounted price of the lamps was $64. After the sale, the remaining lamps were sold without discount. What was the total amount of money collected from selling all 80 lamps?
(a)
The steepest line is from Day 2 to Day 3.
On Day 3, the most number of lamps was sold.
(b)
Number of lamps that were left at Day 4 = 40
Number of lamps that were sold for the first four days
= 80 - 40
= 40
Percentage of lamps that were sold for the first four days
=
4080 x 100%
= 50%
(c)
Number of lamps that were left at the end of the sale = 20
Number of lamps that were sold during the sale
= 80 - 20
= 60
Total amount that collected from the lamps sold
= 60 x 64
= $3840
Price of each lamp after 20% discount
= 100% - 20%
= 80%
80% of the price = 64
1% of the price = 64 ÷ 80 = 0.8
100% of the price = 100 x 0.8 = 80
Amount collected from selling the remaining lamps
= 20 x 80
= $1600
Total amount collected from selling all the 80 lamps
= 3840 + 1600
= $5440
Answer(s): (a) Day 3; (b) 50%; (c) $5440