Pei Chun Public Sch 2007 PSLE Math Prelim Q43

Taufik arranged a rectangle and a square and painted them in three colours as shown in the figure below. The ratio of the area of the rectangle to that of the square is 3:1. The ratio of the area of the red part to that of the blue part is 4:1. The length of the square is 9 cm.
a) What is the area of the purple part?
b) What is the ratio of the area of the purple part to that of the figure?






Area of Rectangle : Area of Square
3 : 1
9 units : 3 units

Red Area : Blue Area
4 : 1
8 units : 2 units

a)
(Square) 3 units ----- 81 square cm
(Purple) 1 unit ----- 81 square cm divided by 3 = 27 square cm (Answer)

b)
Purple ----- 1 unit
Whole figure 11 units

Area of purple part : Area of whole figure
1 : 11 (Answer)