PSLE
Bookstores Q and R sell files of four colours. The bar graphs show the number of files sold by each shop in July. The bar for the number pink files sold by Bookstore Q has not been drawn.

1. Half of the files sold by Bookstore Q were pink files. How many pink files did Bookstore Q sell?
2. Which colour(s) of files did Bookstore Q sell less than Bookstore R? Give your answer(s) in letter(s) in alphabetical order. (Eg Blue, Red = B, R)
3. In August, Bookstore R sold 30 less yellow files than the number of yellow files sold in July. What was the percentage increase in the number of yellow files sold by Bookstore R from July to August?

(a)
Number of green files sold in Bookstore Q = 100
Number of yellow files sold in Bookstore Q = 180
Number of orange files sold in Bookstore Q = 80

Since pink files sold in Bookstore Q is half of the files sold by Bookstore Q, the total of yellow files, orange files and green files is equal to pink files.

Number of pink files sold in Bookstore Q
= 180 + 80 + 100
= 360

(b)
Number of green files sold in Bookstore Q = 100 (Less) 
Number of green files sold in Bookstore R = 160

Number of yellow files sold in Bookstore Q = 180 (More)
Number of yellow files sold in Bookstore R = 60

Number of orange files sold in Bookstore Q = 80 (Equal)
Number of orange files sold in Bookstore R = 80

Number of pink files sold in Bookstore Q = 360 (More) 
Number of pink files sold in Bookstore R = 160 

Colour(s) of files that Bookstore Q sold less than Bookstore R = Green (G)

(c)
Percentage decrease in the number of yellow files sold by Bookstore R from July to August
= ³⁰₆₀ x 100%
= ¹₂ x 100%
= 50%

Answer(s): (a) 360; (b) G; (c) 50%