Area Problems Find the length of a rope by which a cow must be tethered in order that it may be able to graze an area of 154 sq m. 12 m 7 m 8 m 13 m 12 m 7 m 8 m 13 m ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Length of to the rope = Radius of circle According to the question,?r2 = 154 ? r2 = 154 x (7/22) = 7 x 7 = 49 ? r = ?49 = 7 m
Area Problems The ratio between the lenght and the breadth of a rectangle is 2 : 1. If breadth is 5 cm less than the length, what will be the parimeter of the rectangle? 30 cm 25 cm 40 cm 35 cm 30 cm 25 cm 40 cm 35 cm ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let length = 2x and breadth = xAccording to the question, 2x - x = 5 ? x = 5? Required perimeter = 2(2x + x) = 6x= 30 cm
Area Problems The difference between the circumference and the radius of a circle is 37 cm. The area of a circle is? 148 sq. cm 154 sq. cm 259 sq. cm 111 sq. cm 148 sq. cm 154 sq. cm 259 sq. cm 111 sq. cm ANSWER EXPLANATION DOWNLOAD EXAMIANS APP ? 2?r - r = 37? [(2 x 22/7) -1]r= 37? 37r / 7= 37? r = 7 So, area of the circle =(22/7) x 7 x 7 cm2= 154 cm2
Area Problems If the base of a rectangular is increased by 10% and the area is unchanged , then the corresponding altitude must to be decreased by? 11% 10% 91/11 % 111/9 % 11% 10% 91/11 % 111/9 % ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let base = b and altitude = h Then, Area = b x h But New base = 110b / 100 = 11b / 10Let New altitude = HThen, Decrese = (h - 10h /11 )= h / 11? Required decrease per cent = (h/11) x (1 / h ) x 100 %= 91/11 %
Area Problems A hall 20 m long and 15 m broad is surrounded by a verandah of uniform width of 2.5 m. the cost of flooring the verandah at the rate of 3.50 per sq. meter is? Rs. 600 Rs. 700 Rs. 800 Rs. 500 Rs. 600 Rs. 700 Rs. 800 Rs. 500 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Area of verandah = [(25 x 20) -(20 x 15)] m2= 200 m2? Cost of flooring = Rs. (200 x 3.50)= Rs. 700
Area Problems An error 2% in excess is made while measuring the side of a square. The percentage of error in the calculated area of the square is: 2% 4% 4.04% 2.02% 2% 4% 4.04% 2.02% ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 100 cm is read as 102 cm. ∴ A1 = (100 x 100) cm2 and A2 (102 x 102) cm2. (A2 - A1) = [(102)2 - (100)2] = (102 + 100) x (102 - 100) = 404 cm2. ∴ Percentage error = ❨ 404 x 100 ❩% = 4.04%
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