Area Problems The sides of a triangular board are 13 meters, 14 meters and 15 meters. The cost of paining it at the rate of Rs. 8.75 per m 2 is? Rs. 722.50 Rs. 688.80 Rs. 730.80 Rs. 735 Rs. 722.50 Rs. 688.80 Rs. 730.80 Rs. 735 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP s = (13 + 14 + 15 ) / 2 = 21, s-a = 8 , s-b = 7, s-c= 6? Area to be painted = ? [s(s-a) (s-b) (s-c)]=? [21 x 8 x 7 x 6] m2= 84 m2? Cost of painting = Rs. (84 x 8.75) = Rs. 735
Area Problems The ratio of the radii of two circle is 1:3 the radio of their areas is? 1:3 None of these 1:9 1:6 1:3 None of these 1:9 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 If the radius of a circle is decreased by 50% , find the percentage decrease in its area. 35% 75% 25% 65% 35% 75% 25% 65% ANSWER EXPLANATION DOWNLOAD EXAMIANS APP let original radius = r and new radius = (50/100) r = r/2 original area = ?r 2 and new area = ? r / 2 2 decrease in area = 3 ?r 2 / 4 * 1 ?r 2 *100 = 75%
Area Problems The length and breadth of a playground are 36 m and 21 m respectively. Flagstaffs are required to be fixed on all along the boundary at a distance of 3 m apart. The number of flagstaffs will be? 40 39 38 37 40 39 38 37 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Perimeter = 2 x (36 + 21 ) m = 144 m ? Number of flagstaffs = 144 / 3 = 38
Area Problems The inner circumference of a circular race track, 14 m wide, is 440 m. Find radius of the outer circle 84 33 22 44 84 33 22 44 ANSWER DOWNLOAD EXAMIANS APP
Area Problems The area of a circle of radius 5 is numerically what percent its circumference? 350% 150% 250% 450% 350% 150% 250% 450% ANSWER DOWNLOAD EXAMIANS APP
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