PSLE
Stationery Kiosks A and B 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 Stationery Kiosk A has not been drawn.

1. Half of the folders sold by Stationery Kiosk A were purple folders. How many purple folders did Stationery Kiosk A sell?
2. Which colour(s) of folders did Stationery Kiosk A sell less than Stationery Kiosk B? Give your answer(s) in letter(s) in alphabetical order. (Eg Blue, Red = B, R)
3. In July, Stationery Kiosk B sold 40 less yellow folders than the number of yellow folders sold in June. What was the percentage increase in the number of yellow folders sold by Stationery Kiosk B from June to July?

(a)
Number of blue folders sold in Stationery Kiosk A = 60
Number of yellow folders sold in Stationery Kiosk A = 180
Number of green folders sold in Stationery Kiosk A = 180

Since purple folders sold in Stationery Kiosk A is half of the folders sold by Stationery Kiosk A, the total of yellow folders, green folders and blue folders is equal to purple folders.

Number of purple folders sold in Stationery Kiosk A
= 180 + 180 + 60
= 420

(b)
Number of blue folders sold in Stationery Kiosk A = 60 (Less) 
Number of blue folders sold in Stationery Kiosk B = 180

Number of yellow folders sold in Stationery Kiosk A = 180 (More)
Number of yellow folders sold in Stationery Kiosk B = 80

Number of green folders sold in Stationery Kiosk A = 180 (Equal)
Number of green folders sold in Stationery Kiosk B = 180

Number of purple folders sold in Stationery Kiosk A = 420 (More) 
Number of purple folders sold in Stationery Kiosk B = 120 

Colour(s) of folders that Stationery Kiosk A sold less than Stationery Kiosk B = Blue (B)

(c)
Percentage decrease in the number of yellow folders sold by Stationery Kiosk B from June to July
= ⁴⁰₈₀ x 100%
= ¹₂ x 100%
= 50%

Answer(s): (a) 420; (b) B; (c) 50%