Area Problems
The cost of cultivating a square field at the rate of Rs. 160 per hectare is Rs. 1440. the cost of putting a fence around it at 75 paisa per meter is?
Area = 1440 / 160 hectares = 9 hectares = 90000 m2? One side = ?90000 m = 300 mSo perimeter = 4 x 300 m = 1200 m ? Cost of fencing = Rs (1200 x 75) / 100= Rs. 900
Let l = 4k and b = 9kArea of rectangle = l x b144 = 4k x 9k ? k2 = 144/36 ? k2 = 4? k = 2? l = 8 cm and b = 18 cmPerimeter of rectangle = 2(l + b)= 2(8 + 18)= 2 x 26= 52 cm
According to the question,l/[2(l + b)] = 5/18? 10l + 10b = 18l = 10b? l/b = 10/8 = 5/4? l : b = 5 : 4Hence, ratio of length and breadth of a rectangle is 5 : 4
Area of the field = Total cost/rate = (333.18/25.6) = 13.5 hectares 13 . 5 * 10000 m 2 = 135000 m 2 Let altitude = x metres and base = 3x metres.Then, 1 2 * 3 x * x = 135000 ? x 2 = 90000 ? x = 300 Base = 900 m and Altitude = 300 m.
EXAMIANS