PSLE
Stationery Shops R and S sell staplers of four colours. The bar graphs show the number of staplers sold by each shop in May. The bar for the number yellow staplers sold by Stationery Shop R has not been drawn.

1. Half of the staplers sold by Stationery Shop R were yellow staplers. How many yellow staplers did Stationery Shop R sell?
2. Which colour(s) of staplers did Stationery Shop R sell less than Stationery Shop S? Give your answer(s) in letter(s) in alphabetical order. (Eg Blue, Red = B, R)
3. In June, Stationery Shop S sold 15 more green staplers than the number of green staplers sold in May. What was the percentage increase in the number of green staplers sold by Stationery Shop S from May to June?

(a)
Number of green staplers sold in Stationery Shop R = 35
Number of purple staplers sold in Stationery Shop R = 40
Number of blue staplers sold in Stationery Shop R = 10

Since yellow staplers sold in Stationery Shop R is half of the staplers sold by Stationery Shop R, the total of green staplers, purple staplers and blue staplers is equal to yellow staplers.

Number of yellow staplers sold in Stationery Shop R
= 35 + 40 + 10
= 85

(b)
Number of green staplers sold in Stationery Shop R = 35 (More)
Number of green staplers sold in Stationery Shop S = 25

Number of purple staplers sold in Stationery Shop R = 40 (Equal)
Number of purple staplers sold in Stationery Shop S = 40

Number of blue staplers sold in Stationery Shop R = 10 (Less) 
Number of blue staplers sold in Stationery Shop S = 35

Number of yellow staplers sold in Stationery Shop R = 85 (More) 
Number of yellow staplers sold in Stationery Shop S = 40 

Colour(s) of staplers that Stationery Shop R sold less than Stationery Shop S = Blue (B)

(c)
Percentage increase in the number of green staplers sold by Stationery Shop S from May to June
= ¹⁵₂₅ x 100%
= ³₅ x 100%
= 60%

Answer(s): (a) 85; (b) B; (c) 60%