PSLE
Bookstores S and T sell files of four colours. The bar graphs show the number of files sold by each shop in June. The bar for the number blue files sold by Bookstore S has not been drawn.

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

(a)
Number of purple files sold in Bookstore S = 180
Number of yellow files sold in Bookstore S = 160
Number of green files sold in Bookstore S = 40

Since blue files sold in Bookstore S is half of the files sold by Bookstore S, the total of purple files, yellow files and green files is equal to blue files.

Number of blue files sold in Bookstore S
= 180 + 160 + 40
= 380

(b)
Number of purple files sold in Bookstore S = 180 (More)
Number of purple files sold in Bookstore T = 100

Number of yellow files sold in Bookstore S = 160 (Equal)
Number of yellow files sold in Bookstore T = 160

Number of green files sold in Bookstore S = 40 (Less) 
Number of green files sold in Bookstore T = 160

Number of blue files sold in Bookstore S = 380 (More) 
Number of blue files sold in Bookstore T = 80 

Colour(s) of files that Bookstore S sold less than Bookstore T = Green (G)

(c)
Percentage increase in the number of purple files sold by Bookstore T from June to July
= ³⁰₁₀₀ x 100%
= ³₁₀ x 100%
= 30%

Answer(s): (a) 380; (b) G; (c) 30%