PSLE
Bookstores J and K sell folders of four colours. The bar graphs show the number of folders sold by each shop in June. The bar for the number purple folders sold by Bookstore J has not been drawn.

1. Half of the folders sold by Bookstore J were purple folders. How many purple folders did Bookstore J sell?
2. Which colour(s) of folders did Bookstore J sell less than Bookstore K? Give your answer(s) in letter(s) in alphabetical order. (Eg Blue, Red = B, R)
3. In July, Bookstore K sold 10 less orange folders than the number of orange folders sold in June. What was the percentage increase in the number of orange folders sold by Bookstore K from June to July?

(a)
Number of green folders sold in Bookstore J = 100
Number of orange folders sold in Bookstore J = 150
Number of pink folders sold in Bookstore J = 150

Since purple folders sold in Bookstore J is half of the folders sold by Bookstore J, the total of orange folders, pink folders and green folders is equal to purple folders.

Number of purple folders sold in Bookstore J
= 150 + 150 + 100
= 400

(b)
Number of green folders sold in Bookstore J = 100 (Less) 
Number of green folders sold in Bookstore K = 225

Number of orange folders sold in Bookstore J = 150 (More)
Number of orange folders sold in Bookstore K = 100

Number of pink folders sold in Bookstore J = 150 (Equal)
Number of pink folders sold in Bookstore K = 150

Number of purple folders sold in Bookstore J = 400 (More) 
Number of purple folders sold in Bookstore K = 100 

Colour(s) of folders that Bookstore J sold less than Bookstore K = Green (G)

(c)
Percentage decrease in the number of orange folders sold by Bookstore K from June to July
= ¹⁰₁₀₀ x 100%
= ¹₁₀ x 100%
= 10%

Answer(s): (a) 400; (b) G; (c) 10%