24) A

Firstly, it is important that you realise that radius of cylinder = radius of hemisphere.

Volume of solid = Volume of cylinder + volume of hemisphere

Volume of cylinder = π r² l

Volume of hemisphere = ⅔ π r³

π r² l +  ⅔ π r³ = π r² (l + ⅔ r)

If you multiply the whole thing by 3, you will get

π r² / 3 (3l + 2 r)

Hence, A is the answer.