# Question

Thanks

If area of the shaded area is  u cm²,

Area of B = 128 + u

Area of A = (128 +  u) * 60/100

= (384 + 3u) / 5

Given 60% of Area A is shaded

(384 + 3u )/5 * (60/100) = u

12(384 + 3u )/100 = u                  multiply both sides by 100

4608 + 36u = 100u

64u =4608

u = 72

Area of the figure = Area A + Area B -u

=(384 + 3u) / 5 + 128 + u – u

= 120 + 128

= 248

Area of the figure is 248 cm².

Check:

128 + 72 = 200

200 * 60/100 = 120

120 * 60/100 = 72 (Checked)

0 Replies 1 Like ✔Accepted Answer

When A = 60% of B,

60% of A = 60% × (60% of B)

= 36% of B

100% – 36% = 64% (unshaded of B)

64% -> 128 cm^2

100% -> 128 ÷ 64 × 100 = 200cm^2 (area of B)

Area of A -> 60% × 200 = 120cm^2

Total area: 120 + 128 = 248 cm^2 //

0 Replies 2 Likes

If shaded area is u cm²,

Area B = 128 + u

Area A =  60% of Area B = 60(128 + u )/100= 3(128 + u )/5

60% of A = u

(3/5) * 3(128 + u )/5 = u

9(128 + u )/25 = u           multiply both sides by 25

1152 + 9u = 25u

16u = 1152

u = 72

Area of the figure = Area B + 40% of Area A

= 128 + 72 + (2/5) * 3(128 + 72 )/5

= 200 + 48

= 248

Area of the figure is 248 cm²

0 Replies 1 Like