Area Problems The ratio of the radii of two circle is 1:3 the radio of their areas is? None of these 1:9 1:3 1:6 None of these 1:9 1:3 1:6 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP The Radio of areas = area of first circle : area of 2nd circle= ?r2 / ?(3r)2= ?r2/ 9 ?r2= 1/9 = 1: 9
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. B=600;H=700 B=900;H=300 B=300;H=900 B=500;H=900 B=600;H=700 B=900;H=300 B=300;H=900 B=500;H=900 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 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.
Area Problems If the diagonal of a square is double, how does the area of the square change? None of these Becomes two fold Becomes three fold Becomes four fold None of these Becomes two fold Becomes three fold Becomes four fold ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Ratio of the areas = area of original square / area of new square = [ d2 / 2 ] / [ (2d)2 / 2 ] = 1/4? New area becomes 4 fold.
Area Problems A tank is 25m long 12m wide and 6m deep. The cost of plastering its walls and bottom at 75 paise per sq m is Rs. 558 Rs. 458 Rs. 358 Rs. 258 Rs. 558 Rs. 458 Rs. 358 Rs. 258 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Area to be plastered = 2 l + b × h + l × b = 2 25 + 12 × 6 + 25 × 12 = 744 s q . m Cost of plastering = 744 × 75 100 = R s . 558
Area Problems The area of circle inscribed in an equilateral triangle is 462 cm . The perimeter of the triangle is? 72.6 cms 126 cms 168 cms 42 ? 3 cms 72.6 cms 126 cms 168 cms 42 ? 3 cms ANSWER EXPLANATION DOWNLOAD EXAMIANS APP ? 22/7 x r2 = 462? r2 = (462 x 7) /22 = 147? r = 7?3 cm ? Height of the triangle = 3r = 21?3 cmNow, ? a2 = a2/4 + (3r)2? 3a2/4 = (21?3)2? a2 = (1323 x 4)/3? a = 21x 2 = 42 cm? Perimeter = 3a = 3 x 42=126 cm
Area Problems The base of a parallelogram is twice its height. If the area of the parallelogram is 338 sq.cm. Find its height? 16 cm 13 cm 12 cm 14 cm 16 cm 13 cm 12 cm 14 cm ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let height =x Then, base =2x 2x * x = 338 =>x=13
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