Area Problems A wheel make 4000 revolution in moving a distance of 44 km. Find the radius of the wheel. 28 m 27 m 25 m 1.75 m 28 m 27 m 25 m 1.75 m ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Distance covered in 1 revolution = (44 x 1000) / 4000 = 11 mAccording to the question, 2?r = 11 ? (44/7) x r = 11? r = (11 x 7) / 44 = 1.75 m
Area Problems The length of a rectangle is double while its breadth is halved. What is the percentage change in area? 50 No change None of these 75 50 No change None of these 75 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let length = l and breadth = bThen, area = lb New length = 2lAnd new breadth = b/2 ? New area = ( 2l ) x (b/2) = lbSo, there is no change in area .
Area Problems A rectangular lawn 55m by 35m has two roads each 4m wide running in the middle of it. One parallel to the length and the other parallel to breadth. The cost of graveling the roads at 75 paise per sq meter is rs.358 rs.258 rs.158 rs.58 rs.358 rs.258 rs.158 rs.58 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP area of cross roads = (55 x 4) + (35 x 4)- (4 x 4) = 344sq m cost of graveling = 344 x (75/100) = Rs. 258
Area Problems A rectangle has 15 cm as its length and 150 cm 2 as its area .Its area is increased to 1 1 / 3 times the original area by increasing only its length . Its new perimeter is? 80 cm 70 cm 60 cm 50 cm 80 cm 70 cm 60 cm 50 cm ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Breadth of the rectangle = (150/15) cm= 10 cmNew area = (4/3 x 150) cm2= 200 cm2New length = 200/10 cm=20 cmNew perimeters = 2(20 + 10) cm= 60 cm
Area Problems The radius of the wheel of a vehicle is 70 cm. The wheel makes 10 revolutions in 5 seconds. The speed of the vehicle is? 29.46 km/hr. 36.25 km/hr. 31.68 km/hr. 32.72 km/hr. 29.46 km/hr. 36.25 km/hr. 31.68 km/hr. 32.72 km/hr. ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Circumference = 2?r = 2 x (22 / 7) x 70 cm = 440 cm Distance travelled in 10 revolutions = 440 x 10 cm = 4400 cm = 44 m? Speed = distance / time= 44 / 5 m/sec= (44 / 5) x (18 / 5) km/hr = 31.68 km/hr
Area Problems The ratios of areas of two squares, one having its diagonal double than the other is 4:1 2:1 3:1 2:3 4:1 2:1 3:1 2:3 ANSWER DOWNLOAD EXAMIANS APP
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