# A cylindrical tube open at both ends is made of metal. The internal diameter of the tube is 6 cm and length of the tube is 10 cm. If the thickness of the metal used is 1 cm, then the outer curved surface area of the tube is

 [ A ]    140Ï€sq cm [ B ]    146.5Ï€ sq cm [ C ]    70Ï€sq cm [ D ]    None of these
 Answer : Option D Explanation :