PSLE
Stores B and C sell notebooks of four colours. The bar graphs show the number of notebooks sold by each shop in May. The bar for the number blue notebooks sold by Store B has not been drawn.

1. Half of the notebooks sold by Store B were blue notebooks. How many blue notebooks did Store B sell?
2. Which colour(s) of notebooks did Store B sell less than Store C? Give your answer(s) in letter(s) in alphabetical order. (Eg Blue, Red = B, R)
3. In June, Store C sold 20 more orange notebooks than the number of orange notebooks sold in May. What was the percentage increase in the number of orange notebooks sold by Store C from May to June?

(a)
Number of orange notebooks sold in Store B = 140
Number of green notebooks sold in Store B = 80
Number of purple notebooks sold in Store B = 100

Since blue notebooks sold in Store B is half of the notebooks sold by Store B, the total of orange notebooks, green notebooks and purple notebooks is equal to blue notebooks.

Number of blue notebooks sold in Store B
= 140 + 80 + 100
= 320

(b)
Number of orange notebooks sold in Store B = 140 (More)
Number of orange notebooks sold in Store C = 100

Number of green notebooks sold in Store B = 80 (Equal)
Number of green notebooks sold in Store C = 80

Number of purple notebooks sold in Store B = 100 (Less) 
Number of purple notebooks sold in Store C = 180

Number of blue notebooks sold in Store B = 320 (More) 
Number of blue notebooks sold in Store C = 160 

Colour(s) of notebooks that Store B sold less than Store C = Purple (P)

(c)
Percentage increase in the number of orange notebooks sold by Store C from May to June
= ²⁰₁₀₀ x 100%
= ¹₅ x 100%
= 20%

Answer(s): (a) 320; (b) P; (c) 20%