PSLE
School camp sweaters were available in 4 colours: brown, white, purple and green. At the camp, each students chose one sweater. The pie chart represents the students' choice of sweater colours. 33 students chose white sweaters. The students' choice of sweater colours is also represented by the bar graph. The bar that shows the number of students who chose purple sweaters has not been drawn. How many students chose purple sweaters?

    
From the pie graph,
fraction of students who chose brown or green
= ^90°_360°
= ¹₄

From the bar graph,
Number of students who chose brown = Number of students who chose green = 45 

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

Total number of students = 180

Number of students who chose purple sweaters
= 180 - 45 - 45 - 33
= 57

Answer(s): 57