PSLE
Stationery Shops E and F sell post-it-pads of four colours. The bar graphs show the number of post-it-pads sold by each shop in October. The bar for the number blue post-it-pads sold by Stationery Shop E has not been drawn.

1. Half of the post-it-pads sold by Stationery Shop E were blue post-it-pads. How many blue post-it-pads did Stationery Shop E sell?
2. Which colour(s) of post-it-pads did Stationery Shop E sell less than Stationery Shop F? Give your answer(s) in letter(s) in alphabetical order. (Eg Blue, Red = B, R)
3. In November, Stationery Shop F sold 10 less pink post-it-pads than the number of pink post-it-pads sold in October. What was the percentage increase in the number of pink post-it-pads sold by Stationery Shop F from October to November?

(a)
Number of orange post-it-pads sold in Stationery Shop E = 125
Number of pink post-it-pads sold in Stationery Shop E = 250
Number of yellow post-it-pads sold in Stationery Shop E = 175

Since blue post-it-pads sold in Stationery Shop E is half of the post-it-pads sold by Stationery Shop E, the total of pink post-it-pads, yellow post-it-pads and orange post-it-pads is equal to blue post-it-pads.

Number of blue post-it-pads sold in Stationery Shop E
= 250 + 175 + 125
= 550

(b)
Number of orange post-it-pads sold in Stationery Shop E = 125 (Less) 
Number of orange post-it-pads sold in Stationery Shop F = 225

Number of pink post-it-pads sold in Stationery Shop E = 250 (More)
Number of pink post-it-pads sold in Stationery Shop F = 25

Number of yellow post-it-pads sold in Stationery Shop E = 175 (Equal)
Number of yellow post-it-pads sold in Stationery Shop F = 175

Number of blue post-it-pads sold in Stationery Shop E = 550 (More) 
Number of blue post-it-pads sold in Stationery Shop F = 75 

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

(c)
Percentage decrease in the number of pink post-it-pads sold by Stationery Shop F from October to November
= ¹⁰₂₅ x 100%
= ²₅ x 100%
= 40%

Answer(s): (a) 550; (b) O; (c) 40%