PSLE
Shops C and D sell staplers of four colours. The bar graphs show the number of staplers sold by each shop in May. The bar for the number blue staplers sold by Shop C has not been drawn.

1. Half of the staplers sold by Shop C were blue staplers. How many blue staplers did Shop C sell?
2. Which colour(s) of staplers did Shop C sell less than Shop D? Give your answer(s) in letter(s) in alphabetical order. (Eg Blue, Red = B, R)
3. In June, Shop D sold 10 more pink staplers than the number of pink staplers sold in May. What was the percentage increase in the number of pink staplers sold by Shop D from May to June?

(a)
Number of pink staplers sold in Shop C = 200
Number of orange staplers sold in Shop C = 150
Number of yellow staplers sold in Shop C = 50

Since blue staplers sold in Shop C is half of the staplers sold by Shop C, the total of pink staplers, orange staplers and yellow staplers is equal to blue staplers.

Number of blue staplers sold in Shop C
= 200 + 150 + 50
= 400

(b)
Number of pink staplers sold in Shop C = 200 (More)
Number of pink staplers sold in Shop D = 25

Number of orange staplers sold in Shop C = 150 (Equal)
Number of orange staplers sold in Shop D = 150

Number of yellow staplers sold in Shop C = 50 (Less) 
Number of yellow staplers sold in Shop D = 150

Number of blue staplers sold in Shop C = 400 (More) 
Number of blue staplers sold in Shop D = 150 

Colour(s) of staplers that Shop C sold less than Shop D = Yellow (Y)

(c)
Percentage increase in the number of pink staplers sold by Shop D from May to June
= ¹⁰₂₅ x 100%
= ²₅ x 100%
= 40%

Answer(s): (a) 400; (b) Y; (c) 40%