Answer:
A = 76.85
B =65.28
Step-by-step explanation:
(30/100)A = 10 + (20/100)B
0.3A - 0.2B = 10 ...... equation (i)
(30/100)B + 35 = (20/100)A
0.2A - 0.3B = 35 ........ equation (ii)
From equation (i)
0.3A = 10 - 0.2B
A = (10 - 0.2b) / 0.3
A = 33.33 - 0.67B ........equation (iii)
Put equation (iii) into equation (ii)
0.2(33.33 - 0.67B) - 0.3B = 35
6.67 - 0.134B - 0.3B = 35
0.434B = 35 - 6.67
B = 28.33 / 0.434
B = 65. 275 = 65.28
Put B = 65.28 into equation (i)
0.3A - 0.2B = 10
0.3A - 0.2(65.28) = 10
0.3A - 13.056 = 10
0.3A = 10 + 13.056
A = 23.056/ 0.3
A = 76.85
A of trapezium = ((a+b)/2)(h)
A = ((10+10+4)/2)(8)
A = (24/2)(8)
A = 12(8)
A = 94
The area is 94ft²
49% = 50% - 1%
So half of 162 is 81. 1% of 162 is about 2
So 49% ~ 81 - 2 ~79
(actual value is 79.38)
