A metallic sphere of radius 10.5 cm is melted and recast into small right circular cones, each of base radius 3.5 cm and height 3 cm. The number of cones so formed is (a) 105 (b) 113 (c) 126 (d) 135

Explanation

solid sphere radius `=10.5cm`
cone radius `=3.5cm`
cone height `=3cm`
volume of sphere =no.of cone xx volume of each cone
`4/3pir^3=nxx1/3piR^2xxh`
`4xx(10.5)^3=nxx(3.5)^2xx3`
`n=(4xx(10.5)^3)/(3.5^2)xx3`
`n=126`
no. of cone is 126.