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If cost of painting is Rs 12 per sq meter of surface area, how much will it cost to paint all surfaces of a solid right circular cylinder with height of 9 meters and base area of 154 sq meters? |
A) Rs. 8448 B) Rs. 9372 C) Rs. 1540 D) Rs. 3180 Correct Answer : Rs. 8448 Explanation : Base area of cylinder = πr2 = 154 Then, Total Surface Area of cylinder = 2πr(h + r) = 2π*7*(9 + 7) Hence, Cost of painting = 12 * 704 |
If the volume of a cylinder is 2156 cubic cm and height is 14 cm, find its radius? |
A) 14 cm B) 21 cm C) 3.5 cm D) 7 cm Correct Answer : 7 cm Explanation : h = 14 cm, r = ? |
Find the curved surface area of a right circular cylinder of height 35 cm and the base radius 6 cm? |
A) 1220 cm2 B) 1230 cm2 C) 1320 cm2 D) 1330 cm2 Correct Answer : 1320 cm2 Explanation : Curved surface area of cylinder= 2πrh |
The volume of a cuboid is 3600 m3. If its length is 25 m and its breadth and height are in the ratio 4:1 respectively , then the total surface area of the cuboid is ? |
A) 1788 m3 B) 1432 m3 C) 1825 m3 D) 588 m3 Correct Answer : 1788 m3 Explanation : volume of a cuboid, V = LBH (L=length, B = breadth, H=height). Total Surface Area = 2(LB + BH + HL) |
A ball of radius 1 cm is put into a cylindrical pipe so that it fits inside the pipe. If the length of the pipe is 14 m, what is the surface area of the pipe? |
A) 2200 square cm B) 4400 square cm C) 8800 square cm D) 17600 square cm Correct Answer : 8800 square cm Explanation : Radius of cylinder pipe = 1 cm Length or height of cylinder pipe = 14 m = 1400 cm Surface Area of cylinder pipe = 2πrh Surface area of cylinderpipe = 2 × 22/7 × 1 × 1400 Surface Area = 8800 square cm |
If the surface area of a sphere is reduced to one ninth of the area, its radius reduced to ? |
A) One-fourth
B) One-third
C) One-fifth
D) One-ninth Correct Answer : One-third Explanation : Let original and new radius of the sphere are r and R respectively according to the question |
Ice-cream, completely filled in a cylinder of diameter 35 cm and height 32 cm, is to be served by completely filling identical disposable cones of diameter 4 cm and height 7 cm. The maximum number of persons that can be served in this way is? |
A) 950
B) 1000
C) 1050
D) 1100 Correct Answer : 1050 Explanation : Volume of cylinder = πr2h = π * (35/2)2 * 32 Number of persons = Volume of cylinder / Volume of cone |
In a temple there are 25 cylindrical pillars. The radius of each pillar is 28cm and height 4m. The total cost of painting the curved surface area of pillars at the rate of Rs. 8 per m2 is: |
A) Rs. 1408 B) Rs. 1760 C) Rs. 1480 D) Rs. 2520 Correct Answer : Rs. 1408 Explanation : Let radius r = 28 cm, curved surface area of one pillar = 2πrh = 2 x 22/7 x 28 x 400 = 70,400 cm2 Then, curved surface area of 25 pillars = 70400 x 25 = 1760000 cm2 Now, Cost of 25 cylindrical pillars painting = 176 x 8 = Rs 1408 |