1. The lateral area of the cylinder is s1= 2π rh = 2π× 3× 4 = 24π;

The transverse area of the cone is

S2=πrl=π×3×5= 15π

So S2: s1=15π: (24π) = 5: 8.

Second, the cylinder volume V 1=πr? ×h =π×3×3×4 = 36π；

Conical volume V2= 1/3(2πr? ×h)= 1/3(2π×3×3×4)= 12π；

So v2: v1=12π: (36π) =1:3;

So choose a.