PSLE
Stationery Kiosks C and D sell folders of four colours. The bar graphs show the number of folders sold by each shop in October. The bar for the number yellow folders sold by Stationery Kiosk C has not been drawn.

1. Half of the folders sold by Stationery Kiosk C were yellow folders. How many yellow folders did Stationery Kiosk C sell?
2. Which colour(s) of folders did Stationery Kiosk C sell less than Stationery Kiosk D? Give your answer(s) in letter(s) in alphabetical order. (Eg Blue, Red = B, R)
3. In November, Stationery Kiosk D sold 15 more blue folders than the number of blue folders sold in October. What was the percentage increase in the number of blue folders sold by Stationery Kiosk D from October to November?

(a)
Number of blue folders sold in Stationery Kiosk C = 250
Number of pink folders sold in Stationery Kiosk C = 175
Number of purple folders sold in Stationery Kiosk C = 50

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

Number of yellow folders sold in Stationery Kiosk C
= 250 + 175 + 50
= 475

(b)
Number of blue folders sold in Stationery Kiosk C = 250 (More)
Number of blue folders sold in Stationery Kiosk D = 50

Number of pink folders sold in Stationery Kiosk C = 175 (Equal)
Number of pink folders sold in Stationery Kiosk D = 175

Number of purple folders sold in Stationery Kiosk C = 50 (Less) 
Number of purple folders sold in Stationery Kiosk D = 250

Number of yellow folders sold in Stationery Kiosk C = 475 (More) 
Number of yellow folders sold in Stationery Kiosk D = 75 

Colour(s) of folders that Stationery Kiosk C sold less than Stationery Kiosk D = Purple (P)

(c)
Percentage increase in the number of blue folders sold by Stationery Kiosk D from October to November
= ¹⁵₅₀ x 100%
= ³₁₀ x 100%
= 30%

Answer(s): (a) 475; (b) P; (c) 30%