Aptitude

Question: The slant height of a right circular cone is 10 m and its height is 8 m. Find the area of its curved surface. [A]. 30 m2 [B]. 40 m2 [C]. 60 m2 [D]. 80 m2 Answer: Option C Explanation: l = 10 m, h = 8 m. So, r = l2 – h2…

Question: A right triangle with sides 3 cm, 4 cm and 5 cm is rotated the side of 3 cm to form a cone. The volume of the cone so formed is: [A]. 12 cm3 [B]. 15 cm3 [C]. 16 cm3 [D]. 20 cm3 Answer: Option A Explanation: Clearly, we have r = 3 cm…

Question: A hollow iron pipe is 21 cm long and its external diameter is 8 cm. If the thickness of the pipe is 1 cm and iron weighs 8 g/cm3, then the weight of the pipe is: [A]. 3.6 kg [B]. 3.696 kg [C]. 36 kg [D]. 36.9 kg Answer: Option B Explanation: External radius…

Question: 66 cubic centimetres of silver is drawn into a wire 1 mm in diameter. The length of the wire in metres will be: [A]. 84 [B]. 90 [C]. 168 [D]. 336 Answer: Option A Explanation: Let the length of the wire be h. Radius = 1 mm = 1 cm. Then, 2 20 22…

Question: The curved surface area of a cylindrical pillar is 264 m2 and its volume is 924 m3. Find the ratio of its diameter to its height. [A]. 3 : 7 [B]. 7 : 3 [C]. 6 : 7 [D]. 7 : 6 Answer: Option B Explanation: r2h = 924         r…

Question: A cistern of capacity 8000 litres measures externally 3.3 m by 2.6 m by 1.1 m and its walls are 5 cm thick. The thickness of the bottom is: [A]. 90 cm [B]. 1 dm [C]. 1 m [D]. 1.1 cm Answer: Option B Explanation: Let the thickness of the bottom be x cm….

Question: A metallic sheet is of rectangular shape with dimensions 48 m x 36 m. From each of its corners, a square is cut off so as to make an open box. If the length of the square is 8 m, the volume of the box (in m3) is: [A]. 4830 [B]. 5120 [C]. 6420…

Question: A hall is 15 m long and 12 m broad. If the sum of the areas of the floor and the ceiling is equal to the sum of the areas of four walls, the volume of the hall is: [A]. 720 [B]. 900 [C]. 1200 [D]. 1800 Answer: Option C Explanation: 2(15 + 12)…

Question: 50 men took a dip in a water tank 40 m long and 20 m broad on a religious day. If the average displacement of water by a man is 4 m3, then the rise in the water level in the tank will be: [A]. 20 cm [B]. 25 cm [C]. 35 cm [D]….

Question: How many bricks, each measuring 25 cm x 11.25 cm x 6 cm, will be needed to build a wall of 8 m x 6 m x 22.5 cm? [A]. 5600 [B]. 6000 [C]. 6400 [D]. 7200 Answer: Option C Explanation: Number of bricks = Volume of the wall = 800 x 600 x…