Two identical cylinders are put together to form a large cylinder 10 cm long. The surface area is reduced by 25.12 square centimeters. The original volume of a cylinder is () cubic centimeters A. 31.4B. 62.8C. 94.2

Two identical cylinders are put together to form a large cylinder 10 cm long. The surface area is reduced by 25.12 square centimeters. The original volume of a cylinder is () cubic centimeters A. 31.4B. 62.8C. 94.2

25.12 △ 2 × (10 △ 2), = 12.56 × 5, = 62.8 (cubic centimeter), a: the volume of a cylinder is 62.8 cubic centimeter