The figure, not drawn to scale, shows a rectangle, CDEF, which is divided in 4 parts, G, H, J, and K. The ratio of the area of K to the area of J is 1 : 3. The ratio of the area of J to the area of H is 7 : 8. If the area of G is 250 cm
2, what is the area of the rectangle CDEF?
K |
J |
H |
G |
1x7 |
3x7 |
|
|
|
7x3 |
8x3 |
|
7 u |
21 u |
24 u |
10 u |
Area J is the repeated identity.
LCM of 3 and 7 = 21
Half of the area of the rectangle
= Area K + Area H
= 7 u + 24 u
= 31 u
Area of G
= Half of the area of the rectangle - Area J
= 31 u - 21 u
= 10 u
10 u = 250
1 u = 250 ÷ 10 = 25
Area of the rectangle
= 31 u x 2
= 62 u
= 62 x 25
= 1550 cm
2 Answer(s): 1550 cm
2