Question

the areas of three rectangle is 3:7:8 . if the average area of the three rectangle is 18cm2,find the different between the biggest rectangle and the smallest rectangle .​

Answer 1

15 sq cm

Explanation:

Let 3x = area of 1st rectangle

7x = area of 2nd rectangle

8x = area of 3rd rectangle

(3x + 7x + 8x)/3 = 18

3x + 7x + 8x = 54

18x = 54

x = 3

3x = 3(3) = 9 = area of 1st rectangle (smallest)

8x = 8(3) = 24 = area of 3rd rectangle (biggest)

24 - 9 = 15 sq cm