PSLE
Book Shops S and T sell post-it-pads of four colours. The bar graphs show the number of post-it-pads sold by each shop in February. The bar for the number green post-it-pads sold by Book Shop S has not been drawn.

1. Half of the post-it-pads sold by Book Shop S were green post-it-pads. How many green post-it-pads did Book Shop S sell?
2. Which colour(s) of post-it-pads did Book Shop S sell less than Book Shop T? Give your answer(s) in letter(s) in alphabetical order. (Eg Blue, Red = B, R)
3. In March, Book Shop T sold 5 less blue post-it-pads than the number of blue post-it-pads sold in February. What was the percentage increase in the number of blue post-it-pads sold by Book Shop T from February to March?

(a)
Number of orange post-it-pads sold in Book Shop S = 60
Number of blue post-it-pads sold in Book Shop S = 120
Number of purple post-it-pads sold in Book Shop S = 80

Since green post-it-pads sold in Book Shop S is half of the post-it-pads sold by Book Shop S, the total of blue post-it-pads, purple post-it-pads and orange post-it-pads is equal to green post-it-pads.

Number of green post-it-pads sold in Book Shop S
= 120 + 80 + 60
= 260

(b)
Number of orange post-it-pads sold in Book Shop S = 60 (Less) 
Number of orange post-it-pads sold in Book Shop T = 180

Number of blue post-it-pads sold in Book Shop S = 120 (More)
Number of blue post-it-pads sold in Book Shop T = 20

Number of purple post-it-pads sold in Book Shop S = 80 (Equal)
Number of purple post-it-pads sold in Book Shop T = 80

Number of green post-it-pads sold in Book Shop S = 260 (More) 
Number of green post-it-pads sold in Book Shop T = 60 

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

(c)
Percentage decrease in the number of blue post-it-pads sold by Book Shop T from February to March
= ⁵₂₀ x 100%
= ¹₄ x 100%
= 25%

Answer(s): (a) 260; (b) O; (c) 25%