Area Problems The area of the sector of a circle, whose radius is 12 meters and whose angle at the centre is 42, is? 79.2 sq. meters 52.8 sq. meters 39.6 sq. meters 26.4 sq. meters 79.2 sq. meters 52.8 sq. meters 39.6 sq. meters 26.4 sq. meters ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Area of the sector = [(22/7) x 12 x 12] x [42°/360°] m2 = 52.8 m2
Area Problems The inner circumference of a circular race track, 14 m wide, is 440 m. Find radius of the outer circle 44 33 22 84 44 33 22 84 ANSWER DOWNLOAD EXAMIANS APP
Area Problems A rectangle has 20 cm as its length and 200 sq cm as its area. If the area is increased by 1 1/ 5 time the original area by increase its length only then the perimeter of the rectangle so formed (in cm) is 64 72 60 68 64 72 60 68 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP l1 = 20 cm, A1 = 200 sq cm? b1 = 200/20 = 10 cmNow, A2 = 200 x 6/5 = 240 sq cm b2 = 10 cm? l2 = 240/10 = 24 cm? Perimeter of new rectangle = 2(l2 + b2)= 2(24 + 10) = 2 x 34 = 68 cm
Area Problems If the radius of a circle be reduced by 50%. Its area is reduced by? 31.5% 39.5% 34.5% 65.5% 31.5% 39.5% 34.5% 65.5% ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Original area = ? x (r/2)2 = ?r2/4Reduction in area = ? r2 - 3? r2/4? Reduction per cent = [ 3?r2/4 x 4/(?r2) x 100 ] %= 75%
Area Problems The area of sector of a circle of radius 5 cm, formed by an arc of length 3.5 cm is? 35 sq.cms 8. 75 sq.cms 17.5 sq.cms 55 sq.cms 35 sq.cms 8. 75 sq.cms 17.5 sq.cms 55 sq.cms ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Area of sector = ( arc length x radius ) / 2 cm2= (3.5 x 5 ) / 2= 8.75 cm2
Area Problems The cost of papering the four walls of a room is Rs. 48. Each one of length, breadth and height of another room is double that of this room.The cost of papering the walls of the new room is? Rs. 384 Rs. 96 Rs. 298 Rs. 192 Rs. 384 Rs. 96 Rs. 298 Rs. 192 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the length, breadth and height of the room be l, b and h respectively As per question Cost of 2(l + b) x h = Rs. 48 ? Required cost = cost of 2 (2l + 2b) x 2h= cost of 4 [2(l + b) x h ]= 4 x Rs. 48= Rs. 192
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