PSLE
Stores H and J sell post-it-pads of four colours. The bar graphs show the number of post-it-pads sold by each shop in July. The bar for the number yellow post-it-pads sold by Store H has not been drawn.

1. Half of the post-it-pads sold by Store H were yellow post-it-pads. How many yellow post-it-pads did Store H sell?
2. Which colour(s) of post-it-pads did Store H sell less than Store J? Give your answer(s) in letter(s) in alphabetical order. (Eg Blue, Red = B, R)
3. In August, Store J sold 5 less orange post-it-pads than the number of orange post-it-pads sold in July. What was the percentage increase in the number of orange post-it-pads sold by Store J from July to August?

(a)
Number of purple post-it-pads sold in Store H = 40
Number of orange post-it-pads sold in Store H = 80
Number of green post-it-pads sold in Store H = 100

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

Number of yellow post-it-pads sold in Store H
= 80 + 100 + 40
= 220

(b)
Number of purple post-it-pads sold in Store H = 40 (Less) 
Number of purple post-it-pads sold in Store J = 60

Number of orange post-it-pads sold in Store H = 80 (More)
Number of orange post-it-pads sold in Store J = 10

Number of green post-it-pads sold in Store H = 100 (Equal)
Number of green post-it-pads sold in Store J = 100

Number of yellow post-it-pads sold in Store H = 220 (More) 
Number of yellow post-it-pads sold in Store J = 30 

Colour(s) of post-it-pads that Store H sold less than Store J = Purple (P)

(c)
Percentage decrease in the number of orange post-it-pads sold by Store J from July to August
= ⁵₁₀ x 100%
= ¹₂ x 100%
= 50%

Answer(s): (a) 220; (b) P; (c) 50%