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

1. Half of the post-it-pads sold by Stationery Shop R were purple post-it-pads. How many purple post-it-pads did Stationery Shop R sell?
2. Which colour(s) of post-it-pads 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 45 less green post-it-pads than the number of green post-it-pads sold in May. What was the percentage increase in the number of green post-it-pads sold by Stationery Shop S from May to June?

(a)
Number of orange post-it-pads sold in Stationery Shop R = 100
Number of green post-it-pads sold in Stationery Shop R = 160
Number of yellow post-it-pads sold in Stationery Shop R = 80

Since purple post-it-pads sold in Stationery Shop R is half of the post-it-pads sold by Stationery Shop R, the total of green post-it-pads, yellow post-it-pads and orange post-it-pads is equal to purple post-it-pads.

Number of purple post-it-pads sold in Stationery Shop R
= 160 + 80 + 100
= 340

(b)
Number of orange post-it-pads sold in Stationery Shop R = 100 (Less) 
Number of orange post-it-pads sold in Stationery Shop S = 200

Number of green post-it-pads sold in Stationery Shop R = 160 (More)
Number of green post-it-pads sold in Stationery Shop S = 100

Number of yellow post-it-pads sold in Stationery Shop R = 80 (Equal)
Number of yellow post-it-pads sold in Stationery Shop S = 80

Number of purple post-it-pads sold in Stationery Shop R = 340 (More) 
Number of purple post-it-pads sold in Stationery Shop S = 200 

Colour(s) of post-it-pads that Stationery Shop R sold less than Stationery Shop S = Orange (O)

(c)
Percentage decrease in the number of green post-it-pads sold by Stationery Shop S from May to June
= ⁴⁵₁₀₀ x 100%
= ⁹₂₀ x 100%
= 45%

Answer(s): (a) 340; (b) O; (c) 45%