Area Problems A circular road runs rounds a circular ground. If the difference between the circumference of the outer circle and the inner circle is 66 meters, the width of the road is? 21 meters 7 meters 10.5 meters 5.25 meters 21 meters 7 meters 10.5 meters 5.25 meters ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let outer radius be R and inner radius be r.Then from question 2?R - 2?r = 66? 2? (R-r) = 66? (2 x 22)/7 x (R - r) = 66? (R-r) = (66 x 7) / 44= 10.5 m
Area Problems The inner circumference of a circular race track, 14 m wide is 440 m . Then the radius of the outer circle is? 77 m 70 m 84 m 56 m 77 m 70 m 84 m 56 m ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Circumference of a circular = 2?r? 2 x (22 / 7) x r = 440? r = [440 x (7/22) x (1/2)] = 70 m? Radius of outer circle = (70 + 14) m = 84 m
Area Problems The ratio of the radii of two circle is 1:3 the radio of their areas is? 1:9 1:3 None of these 1:6 1:9 1:3 None of these 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 Area of a square is 50 sq. units. Then the area of the circle drawn on its diagonal is? 100? sq. units None of theas 25? sq. units 50? sq. units 100? sq. units None of theas 25? sq. units 50? sq. units ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Area = (Diagonal)2 / 2 = 50? Diagonal = 10 units ? Radius of required circle = 5 unitsIts area = [? x (5)2 ] cm2= 25? units2
Area Problems A circular wire of radius 42 cm is cut and bent in the form of a rectangle whose sides are in the ratio of 6: 5 . The smaller side of the rectangle is? 30 cm 60 cm 72 cm 132 cm 30 cm 60 cm 72 cm 132 cm ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Perimeter of rectangle = Circumference of circle = 2?r=2 x ( 22/7 ) x 42= 264 cm Now perimeter of rectangle = 2 x ( 6a + 5a )? 2 x (6a + 5a) = 264? a = 12Smaller side of rectangle = 5a = 60 cm
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