A hollow iron pipe is 21 cm long and its external diameter is 8 cm. If the thickness of the pipe is 1 cm and iron weighs 8 g/cm3, then the weight of the pipe is: April 21, 2025August 7, 2019 A.3.6 kg B.3.696 kg C.36 kg D.36.9 kg Show AnswerAnswer=Option B