PSLE
Bookstores V and W sell folders of four colours. The bar graphs show the number of folders sold by each shop in November. The bar for the number yellow folders sold by Bookstore V has not been drawn.

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

(a)
Number of orange folders sold in Bookstore V = 35
Number of pink folders sold in Bookstore V = 35
Number of blue folders sold in Bookstore V = 5

Since yellow folders sold in Bookstore V is half of the folders sold by Bookstore V, the total of orange folders, pink folders and blue folders is equal to yellow folders.

Number of yellow folders sold in Bookstore V
= 35 + 35 + 5
= 75

(b)
Number of orange folders sold in Bookstore V = 35 (More)
Number of orange folders sold in Bookstore W = 20

Number of pink folders sold in Bookstore V = 35 (Equal)
Number of pink folders sold in Bookstore W = 35

Number of blue folders sold in Bookstore V = 5 (Less) 
Number of blue folders sold in Bookstore W = 50

Number of yellow folders sold in Bookstore V = 75 (More) 
Number of yellow folders sold in Bookstore W = 45 

Colour(s) of folders that Bookstore V sold less than Bookstore W = Blue (B)

(c)
Percentage increase in the number of orange folders sold by Bookstore W from November to December
= ¹⁰₂₀ x 100%
= ¹₂ x 100%
= 50%

Answer(s): (a) 75; (b) B; (c) 50%