According to the question, the radii of cone, cylinder and sphere be r and as the heights of cone and cylinder are equal, it will be 2r as the height of sphere is 2r.
CSA of sphere = 4πr²
CSA of cylinder = 2πr x 2r = 4πr² (As h = 2r)
CSA of cone = πrl 
= πr√r² + 4r²
= πr√5r²
= πr²√5

Thus the ratio stands 4πr² : 4πr² :  πr²√5
Removing 2πr² we get 4 : 4 : √5

Hope that helps !!
1 5 1
yeah,now it's correct
i cant believe it --or just refer the same question in www.meritnation. i saw it there as 4:2:root2---WHY and why??
i saw it 4:4:root 5
in meritnation itself