PSLE
School camp sweaters were available in 4 colours: purple, pink, blue and brown. At the camp, each students chose one sweater. The pie chart represents the students' choice of sweater colours. 42 students chose pink sweaters. The students' choice of sweater colours is also represented by the bar graph. The bar that shows the number of students who chose blue sweaters has not been drawn. How many students chose blue sweaters?

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

From the bar graph,
Number of students who chose purple = Number of students who chose brown = 54 

¹₄ of the pie chart = 54
⁴₄ of the pie chart = 4 x 54 = 216

Total number of students = 216

Number of students who chose blue sweaters
= 216 - 54 - 54 - 42
= 66

Answer(s): 66