PSLE
Stores M and N sell notebooks of four colours. The bar graphs show the number of notebooks sold by each shop in July. The bar for the number pink notebooks sold by Store M has not been drawn.

1. Half of the notebooks sold by Store M were pink notebooks. How many pink notebooks did Store M sell?
2. Which colour(s) of notebooks did Store M sell less than Store N? Give your answer(s) in letter(s) in alphabetical order. (Eg Blue, Red = B, R)
3. In August, Store N sold 15 more orange notebooks than the number of orange notebooks sold in July. What was the percentage increase in the number of orange notebooks sold by Store N from July to August?

(a)
Number of orange notebooks sold in Store M = 175
Number of green notebooks sold in Store M = 225
Number of blue notebooks sold in Store M = 50

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

Number of pink notebooks sold in Store M
= 175 + 225 + 50
= 450

(b)
Number of orange notebooks sold in Store M = 175 (More)
Number of orange notebooks sold in Store N = 25

Number of green notebooks sold in Store M = 225 (Equal)
Number of green notebooks sold in Store N = 225

Number of blue notebooks sold in Store M = 50 (Less) 
Number of blue notebooks sold in Store N = 225

Number of pink notebooks sold in Store M = 450 (More) 
Number of pink notebooks sold in Store N = 225 

Colour(s) of notebooks that Store M sold less than Store N = Blue (B)

(c)
Percentage increase in the number of orange notebooks sold by Store N from July to August
= ¹⁵₂₅ x 100%
= ³₅ x 100%
= 60%

Answer(s): (a) 450; (b) B; (c) 60%