PSLE
A company offered $(dn0) kettles at 30% discount during a 7-day sale. The line graph shows the number of kettles left unsold at the end of each day.

1. On which day was the most number of kettles sold? Give your answer in this format. (Eg Day 1)
2. What percentage of the 80 kettles were sold in the first six days of the sale?
3. During the sale, the discounted price of the kettles was $119. After the sale, the remaining kettles were sold without discount. What was the total amount of money collected from selling all 80 kettles?

(a)
Steepest line is from Day 3 to Day 4.

On Day 4, the most number of kettles was sold.

(b)
Number of kettles that were left at Day 6 = 20

Number of kettles that were sold for the first six days
= 80 - 20
= 60

Percentage of kettles that were sold for the first six days
= ⁶⁰₈₀ x 100%
= 75%

(c)
Number of kettles that were left at the end of the sale = 10

Number of kettles that were sold during the sale
= 80 - 10
= 70

Total amount that collected from the kettles sold
= 70 x 119
= $8330

Price of each kettle after 30% discount 
= 100% - 30%
= 70%

70% of the price = 119
1% of the price = 119 ÷ 70 = 1.7
100% of the price = 100 x 1.7 = 170

Amount collected from selling the remaining kettles
= 10 x 170
= $1700

Total amount collected from selling all the 80 kettles
= 8330 + 1700
= $10030

Answer(s): (a) Day 4; (b) 75%; (c) $10030