Area Problems The length of hall is (4/3) times its breadth. If the area of hall be 300 square meters, the difference between the length and the breadth is? None of these 3 meters 15 meters 4 meters None of these 3 meters 15 meters 4 meters ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let breadth = b meters.Then, length = 4b/3 meters.? b x 4b/3 = 300? b2 = 300 x 3/4 ? b2 = 225? b = 15Hence, required difference = [(Length) - (Breadth) ]= 4b/3 - b = b/3= 15/3 m= 5 m
Area Problems The length of a rectangular plot is 20 metres more than its breadth. If the cost of fencing the plot @ 26.50 per metre is Rs. 5300, what is the length of the plot in metres? 40 Data inadequate None of these 120 40 Data inadequate None of these 120 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let breadth = x metres. Then, length = (x + 20) metres. Perimeter = ❨ 5300 ❩ m = 200 m. 26.50 ∴ 2[(x + 20) + x] = 200 ⟹ 2x + 20 = 100 ⟹ 2x = 80 ⟹ x = 40. Hence, length = x + 20 = 60 m
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 13 m 8 m 7 m 12 m 13 m 8 m 7 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 A tank is 25m long 12m wide and 6m deep. The cost of plastering its walls and bottom at 75 paise per sq m is Rs. 558 Rs. 358 Rs. 258 Rs. 458 Rs. 558 Rs. 358 Rs. 258 Rs. 458 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Area to be plastered = 2 l + b × h + l × b = 2 25 + 12 × 6 + 25 × 12 = 744 s q . m Cost of plastering = 744 × 75 100 = R s . 558
Area Problems The wheel of an engine turns 350 times round its axle to cover a distance of 1.76 km. The diameter of the wheel is 9 cm 3 cm 3?3 cm ?3 cm 9 cm 3 cm 3?3 cm ?3 cm ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Distance covered in 1 round = (Total Distance) / (Total round)= (1.76 x 1000)/350= 176/35 m ? 2?r = (1.76 x 100) / 35 cm2? = Diameter = 17600 x 7/22 x 35 = 160 cm
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? 29.46 km/hr. 32.72 km/hr. 31.68 km/hr. 36.25 km/hr. 29.46 km/hr. 32.72 km/hr. 31.68 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
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