PSLE
Bookstores F and G sell notebooks of four colours. The bar graphs show the number of notebooks sold by each shop in November. The bar for the number pink notebooks sold by Bookstore F has not been drawn.

1. Half of the notebooks sold by Bookstore F were pink notebooks. How many pink notebooks did Bookstore F sell?
2. Which colour(s) of notebooks did Bookstore F sell less than Bookstore G? Give your answer(s) in letter(s) in alphabetical order. (Eg Blue, Red = B, R)
3. In December, Bookstore G sold 35 less orange notebooks than the number of orange notebooks sold in November. What was the percentage increase in the number of orange notebooks sold by Bookstore G from November to December?

(a)
Number of yellow notebooks sold in Bookstore F = 75
Number of orange notebooks sold in Bookstore F = 225
Number of purple notebooks sold in Bookstore F = 200

Since pink notebooks sold in Bookstore F is half of the notebooks sold by Bookstore F, the total of orange notebooks, purple notebooks and yellow notebooks is equal to pink notebooks.

Number of pink notebooks sold in Bookstore F
= 225 + 200 + 75
= 500

(b)
Number of yellow notebooks sold in Bookstore F = 75 (Less) 
Number of yellow notebooks sold in Bookstore G = 250

Number of orange notebooks sold in Bookstore F = 225 (More)
Number of orange notebooks sold in Bookstore G = 50

Number of purple notebooks sold in Bookstore F = 200 (Equal)
Number of purple notebooks sold in Bookstore G = 200

Number of pink notebooks sold in Bookstore F = 500 (More) 
Number of pink notebooks sold in Bookstore G = 250 

Colour(s) of notebooks that Bookstore F sold less than Bookstore G = Yellow (Y)

(c)
Percentage decrease in the number of orange notebooks sold by Bookstore G from November to December
= ³⁵₅₀ x 100%
= ⁷₁₀ x 100%
= 70%

Answer(s): (a) 500; (b) Y; (c) 70%