An Important Question of class 10 Based on Mensuration Chapter of M.L Aggarwal for ICSE BOARD.

A metallic sphere of radius 10.5 cm is melted and then recast into small cones, each of radius and height are given.Then you have to find the number of cones thus obtained.

This is the Question Number 23, Exercise 17.5 of M.L Aggarwal.

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# A metallic sphere of radius 10.5 cm is melted and then recast into small cones, each of radius 3.5 cm and height 3 cm. Find the number of cones thus obtained.

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Given radius of the metallic sphere, R = 10.5 cmVolume of the sphere = (4/3)R^{3}= (4/3)×10.5^{3}= 1543.5 cm^{3}Radius of cone, r = 3.5 cmHeight of the cone, h = 3 cmVolume of the cone = (1/3)r^{2}h= (1/3)×3.5^{2}×3= 12.25 cm^{3}Number of cones made from sphere = Volume of sphere / volume of cone= 1543.5 /12.25= 126Hence the number of cones that can be made is 126.