Area Problems A circular piece of thin wire is converted into a rhombus of side 11 cm. Find the diameter of the circular piece? 28 cm 7 cm 3.5 cm 14 cm 28 cm 7 cm 3.5 cm 14 cm ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Circular piece is 4 x 11 = 44 cm long, Then Circumference of circle is given by, 44 = pi x D, where D is the diameter D = 44 / pi Take pi = 22 / 7, then D = 44 / (22/7) = (44 x 7) / 22 D = 14 cm.
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 The diagonals of two squares are in the ratio of 3 : 2. Find the ratio of their areas. 9 : 5 9 : 7 9 : 2 9 : 4 9 : 5 9 : 7 9 : 2 9 : 4 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the diagonals of the squares be 3x and 2x.? Ratio of their areas = [(1/2) (3x2)] / [(1/2) (2x2)] = 9/4
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? 31.68 km/hr. 32.72 km/hr. 29.46 km/hr. 36.25 km/hr. 31.68 km/hr. 32.72 km/hr. 29.46 km/hr. 36.25 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 ratio between the perimeter and the breadth of a rectangle is 5 : 1. If the area of the rectangle is 216 sq. cm, what is the length of the rectangle? None of these Data inadequate 18 cm 24 cm None of these Data inadequate 18 cm 24 cm ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 2(l + b) = 5 b 1 ⟹ 2l + 2b = 5b ⟹ 3b = 2l b = 2 l 3 Then, Area = 216 cm2 ⟹ l x b = 216 ⟹l x 2 l = 216 3 ⟹ l2 = 324 ⟹ l = 18 cm
Area Problems If the diagonals of a rhombus are 4.8 cm 1.4 cm, then what is the perimeter of the rhombus? 12 cm 5 cm 20 cm 10 cm 12 cm 5 cm 20 cm 10 cm ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Perimeter of rhombus= 2 ? d12 + d22 = 2 ?(4.8)2 + (1.4)2= 2 ?23.04 + 1.96 = 2 ?25 = 2 x 5 = 10 cm
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