Area Problems
The base of a triangular field is three times its altitude. If the cost of cultivating the field at Rs. 24.68 per hectare be Rs. 333.18, find its base and height.
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.
? 22/7 x r2 = 13.86 x 10000? r2 = (13.86 x 10000 x 7) / 22? r = 210 m ? Circumference = [2 x (22/7) x 210 ] m = 1320 m Cost of fencing = Rs. (1320 x 20)/100= Rs . 264
Let length of rectangular field = 5y,so width = 4y.From question5y - 4y = 20m? x = 20m ? Length = (5 x 20)m = 100 mBreadth = (4 x 20) m = 80 m ? Perimeter = 2 (100 + 80 ) m = 360 m
Increase in circumference of circle = 5%? Increase in radius is also 5%.Now, increase in area of circle = 2a + (a2/100) %Where, a = increase in radius= 2 x 5 + (5 x 5)/100 % = 10.25%
EXAMIANS