Area Problems The area of a circle of radius 5 is numerically what percent its circumference? 250% 450% 350% 150% 250% 450% 350% 150% ANSWER DOWNLOAD EXAMIANS APP
Area Problems Find the length of a rope by which a cow must be tethered in order that it may be able to graze an area of 154 sq m. 12 m 7 m 13 m 8 m 12 m 7 m 13 m 8 m ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Length of to the rope = Radius of circle According to the question,?r2 = 154 ? r2 = 154 x (7/22) = 7 x 7 = 49 ? r = ?49 = 7 m
Area Problems One diagonal of a rhombus is 60% of the other diagonal. Then, area of the rhombus is how many times the square of the length of the larger diagonal? 3/10 2/5 1/5 6/7 3/10 2/5 1/5 6/7 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let one diagonal be k.Then, other diagonal = (60k/100) = 3k/5 cmArea of rhombus =(1/2) x k x (3k/5) = (3/10) = 3/10 (square of longer diagonal)Hence, area of rhombus is 3/10 times.
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 72 64 60 68 72 64 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? 65.5% 34.5% 31.5% 39.5% 65.5% 34.5% 31.5% 39.5% 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 circle is 38.5 sq. cm. Its circumference is? 6.20 cm 11 cm 22 cm 121 cm 6.20 cm 11 cm 22 cm 121 cm ANSWER EXPLANATION DOWNLOAD EXAMIANS APP ? ( 22 x r2) / 7 = 38.5? r2 =(38.5 x 7) /22? r = 3.5 cm? Circumference = 2 x (22/7) x 3.5 cm= 22 cm
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