Area Problems A tank is 25 m long, 12 m wide and 6 m deep. The cost of plastering its walls and bottom at 75 paise per sq. m, is: Rs. 558 Rs. 458 Rs. 568 Rs. 456 Rs. 558 Rs. 458 Rs. 568 Rs. 456 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Area to be plastered = [2(l + b) x h] + (l x b) = {[2(25 + 12) x 6] + (25 x 12)} m2 = (444 + 300) m2 = 744 m2. ∴ Cost of plastering = Rs. ❨ 744 x 75 ❩ = Rs. 558
Area Problems The area of circle inscribed in an equilateral triangle is 462 cm . The perimeter of the triangle is? 168 cms 72.6 cms 42 ? 3 cms 126 cms 168 cms 72.6 cms 42 ? 3 cms 126 cms ANSWER EXPLANATION DOWNLOAD EXAMIANS APP ? 22/7 x r2 = 462? r2 = (462 x 7) /22 = 147? r = 7?3 cm ? Height of the triangle = 3r = 21?3 cmNow, ? a2 = a2/4 + (3r)2? 3a2/4 = (21?3)2? a2 = (1323 x 4)/3? a = 21x 2 = 42 cm? Perimeter = 3a = 3 x 42=126 cm
Area Problems The area of a rectangle, 144 m long is the same as that of a square having a side 84 m long. The width of the rectangle is? 7 m 14 m 49 m Cannot be determined 7 m 14 m 49 m Cannot be determined ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Area of the square = (84 + 84) m2Area of the rectangle = (144 x width) m2From question both area would be same,? Width = (84 x 84) / 144 m = 49 m
Area Problems The inner circumference of a circular race track, 14 m wide is 440 m . Then the radius of the outer circle is? 70 m 77 m 56 m 84 m 70 m 77 m 56 m 84 m ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Circumference of a circular = 2?r? 2 x (22 / 7) x r = 440? r = [440 x (7/22) x (1/2)] = 70 m? Radius of outer circle = (70 + 14) m = 84 m
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.158 rs.58 rs.358 rs.258 rs.158 rs.58 rs.358 rs.258 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 The altitude of an equilateral triangle of side 2 ? 3 cm is? 1/2 cm 3 cm ? 3/4 ? 3/2 cm 1/2 cm 3 cm ? 3/4 ? 3/2 cm ANSWER EXPLANATION DOWNLOAD EXAMIANS APP ? 1/2 x 2 ? x h = ?3/4 x (2 ?3)2? h = 3 cm.
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