PSLE
School camp blazers were available in 4 colours: gold, white, purple and yellow. At the camp, each pupils chose one blazer. The pie chart represents the pupils' choice of blazer colours. 38 pupils chose gold blazers. The pupils' choice of blazer colours is also represented by the bar graph. The bar that shows the number of pupils who chose white blazers has not been drawn. How many pupils chose white blazers?

    
From the pie graph,
fraction of pupils who chose purple or yellow
= ^90°_360°
= ¹₄

From the bar graph,
Number of pupils who chose purple = Number of pupils who chose yellow = 45 

¹₄ of the pie chart = 45
⁴₄ of the pie chart = 4 x 45 = 180

Total number of pupils = 180

Number of pupils who chose white blazers
= 180 - 45 - 45 - 38
= 52

Answer(s): 52