Volume and Surface Area
Practice Questions - Volume and Surface Area
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Q20) Length, breadth and height of a cuboid are in the ratio 1:2:3 and are increased by 10%, 20% and 30% respectively. Find the percentage change in surface area? 1) 71.6% 2) 48.09% 3) 60% 4) None of these  Hence, option 2. Q21) A cone shaped circular tent is 12 m high and the circumference of its circular base is 44 m. How much air is contained in the tent? 1) 308 cu m 2) 462 cu m 3) 616 cu m 4) 924 cu m
Circumference of the base = 44 m  Hence, option 3. Q22) How many bricks, each measuring 25 cm × 15 cm × 8 cm, are required to construct a wall of dimensions 15 m × 6 m × 5 m, when 20% of the volume is occupied by mortar. 1) 75,000 2) 100,000 3) 150,000 4) 120,000
Volume of the wall = 450 m3 Volume of a mortar = 20% of 450 = 90 m3 Volume of a bricks = 360 m3  Hence, option 3. Q23) A rectangular roof is 8 m long and 6 m wide. The rain which falls on the roof is collected in a rectangular cistern 3 m long, 1.5 m wide and 2 m deep. What percentage of the cistern is full after a rainfall of 4 cm? 1) 46.86% 2) 21.33% 3) 12.5% 4) 20%  Hence, option 2. Q24) An open rectangular tank is made up of concrete. The sides are 40 cm thick and the base is 45 cm thick. Internally the tank is 5 m long, 2 m wide and 1.65 m thick. Find it's weight in tonnes if concrete weighs 1000 Kg per 1 cu m. 1) 1760.4 Kg 2) 10716 Kg 3) 16548 Kg 4) 17604 Kg
Volume of concrete = 5.8×2.8×2.1 - 5×2×1.65 = 17.604 cu m Weight of concrete = 17.604×1000 = 17604 Kg Hence, option 4. |