Area Problems The length of a rectangle is double while its breadth is halved. What is the percentage change in area? None of these 50 No change 75 None of these 50 No change 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 The ratio of the area of the circumcircle and the incircle of a square is 1 : ?2 2 : 1 ?2 : 1 1 : 2 1 : ?2 2 : 1 ?2 : 1 1 : 2 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Ratio of the areas of the circumcircle and incircle of a square = [(Diagonal)2?] / [(Side)2?]= [(Side x ?2)2] / (Side)2 = 2/1 or 2 : 1
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 68 60 64 72 68 60 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 The circumferences of two concentric are 176 m and 132 m respectively. what is the difference between their radii? 5 meter 8 meter 7 meter 44 meter 5 meter 8 meter 7 meter 44 meter ANSWER EXPLANATION DOWNLOAD EXAMIANS APP ? 2?R - 2?r = (176-132)? 2?(R-r) = 44? R-r = ( 44 x 7 )/ (2 x 22)= 7 m
Area Problems In a rhombus, whose area is 144 sq.cmone of its diagonal is twice as long as the other, The lengths of its diagonals are? 6 cm, 12 cm 6 ?2 cm, 12?2 cm 24 cm, 48 cm 12 cm, 24 cm 6 cm, 12 cm 6 ?2 cm, 12?2 cm 24 cm, 48 cm 12 cm, 24 cm ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Area of rhombus = (d1 x d2) / 2? (d x 2d ) / 2 = 144? d2 = 144? d = 12 ? Length of diagonal = 12 cm, 24 cm
Area Problems The area of a square is equal to the area of a rectangle. The length of the rectangle is 5 cm more than a side of the square and its breadth is 3 cm less than the side of the square. What is the perimeter of the rectangle ? 26 cm 18 cm 15 cm 34 cm 26 cm 18 cm 15 cm 34 cm ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the side of the square be 's' cm length of rectangle = (s+5) cm breadth of rectangle = (s-3)cm (s+5) (s-3) = s 2 - 5s - 3s - 15 = s 2 2s = 15 Perimeter of rectangle = 2(L+B) = 2(s+5 + s?3) = 2(2s + 2) = 2(15 + 2) = 34 cm
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