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.: 介 介 介, 404, Question 4. If the lateral surface of a, height is 5 cm, then find, surface, (i) radius of its base,, (ii) its volume. (Use t = 3.14), Question, 15.4 Litres, make it?, %3D, %3D, 2nrh = 94.2, Solution, %3D, 2x 3.14 x r x 5 = 94.2, 94.2, 31.4, r = 3 cm, (i) Hence, radius of base, r = 3cm, %3D, (ii) Volume of a cylinder = tr²h= 3.14(3)2 x 5, %3D, = 3.14 x 9x5, = 1413 cm3, Total surfa, Question 5. It costs 2200 to paint the inner curved surface of, cylindrical vessel 10 m deep. If the cost of painting is at the rate, 20 per m2, find, The metal, (i) inner curved surface area of the vessel,, (ii) radius of the base,, (iii) capacity of the vessel., Solution We have, cost to paint the inner curved surface = 2200, Question, cylinder c, %3D, Cost to paint per m? = 20, pencil is 1, Inner curved surface area =, %3D, Cost to paint the inner curved surface, Solution, Cost to paint per, m², 2200, = 110m, %3D, 20, 22, xrx 10= 110, Length of, 110x7, 2 x 220, Also,, 7., r ===1.75 m, %3D, (i) Inner curved surface area of the vessel = 110m, (ii) Hence, radius of the base is 1.75 m., 4., %3D, and, (iii) Capacity of the vessel = Volume of the vessel, %3D, %3D, Hence., 22, 7., 4., 4., 77, %3D, 7., 7., 8., 3D96.25m³