The figure, not drawn to scale, on the right shows 2 rectangles overlapping each other. The ratio of the shaded area to the area of Rectangle R is 3 : 11. The ratio of the shaded area to the area of Rectangle S is 2 : 5. Find the ratio of the unshaded area to the total area of the figure.
Rectangle R |
Shaded Area |
Rectangle S |
11 x 2 |
3 x 2 |
|
|
2 x 3 |
5 x 3 |
22 u |
6 u |
15 u |
The shaded area is the same for both rectangles.
LCM of 2 and 3 = 6
Total area of the figure
= 22 u + 15 u - 6 u
= 31 u
Unshaded area
= 31 u - 6 u
= 25 u
Unshaded area : Total area of the figure
25 : 31
Answer(s): 25 : 31