Area Problems If the sides of a rectangle are increased by 5%, find the percentage increase in its diagonals. 9% 4% 6% 5% 9% 4% 6% 5% ANSWER EXPLANATION DOWNLOAD EXAMIANS APP According to the formula,Percentage increase in diagonals = 5%
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? 36.25 km/hr. 32.72 km/hr. 31.68 km/hr. 29.46 km/hr. 36.25 km/hr. 32.72 km/hr. 31.68 km/hr. 29.46 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 dimensions of a room are 10m x 7m x 5m. There are 2 doors and 3 windows in the room. The dimensions of the doors are 1m x 3m. One window is of size 2m x 1.5m and the other 2 windows are of size 1m x 1.5m. The cost of painting the walls at Rs. 3 per sq m is Rs.374 Rs.274 Rs.174 Rs.474 Rs.374 Rs.274 Rs.174 Rs.474 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Area of 4 walls = 2(l+b)h=2(10+7) x 5 = 170 sq mArea of 2 doors and 3 windows = 2(1x3)+(2x1.5)+2(1x1.5) = 12 sq marea to be planted = 170 -12 = 158 sq m Cost of painting = Rs. 158 x 3 = Rs. 474
Area Problems If the diagonal of a square is double, how does the area of the square change? Becomes two fold Becomes three fold None of these Becomes four fold Becomes two fold Becomes three fold None of these Becomes four fold ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Ratio of the areas = area of original square / area of new square = [ d2 / 2 ] / [ (2d)2 / 2 ] = 1/4? New area becomes 4 fold.
Area Problems if the side of a square be increased by 4 cms. The area increased by 60 sq. cms . The side of the square is? 13 cm 14cm None of these 12 cm 13 cm 14cm None of these 12 cm ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let each side = x cmThen, (x + 4 )2 - x2 = 60? x 2 + 8x + 16 - x2 = 60? x = 5.5 cm
Area Problems The diagonals of two squares are in the ratio of 3 : 2. Find the ratio of their areas. 9 : 4 9 : 2 9 : 5 9 : 7 9 : 4 9 : 2 9 : 5 9 : 7 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
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