A cylindrical metal pipe has a diameter of 20 millimeters and a height of 21 millimeters. A cylindrical hole cut out of the center has a radius of 6 millimeters. Which expressions represent the volume of metal needed, in cubic millimeters, to make the pipe? Check all that apply. 21π (10) 2 - 21π (6) 2 π (20) 2 (21) - π (6) 2 2,100π - 756π 7,644π

1,344

Question

Mathematics

Roach

8 April, 12:06

A cylindrical metal pipe has a diameter of 20 millimeters and a height of 21 millimeters. A cylindrical hole cut out of the center has a radius of 6 millimeters. Which expressions represent the volume of metal needed, in cubic millimeters, to make the pipe? Check all that apply. 21π (10) 2 - 21π (6) 2 π (20) 2 (21) - π (6) 2 2,100π - 756π 7,644π

1,344

+3

Answers (2)

Know the Answer?

Bridget Bridges · Answer 1

Options a and c (1 and 3) are correct

Lucia · Answer 2

Volume of cylinder = πR² x H

Volume of the cylinder = π (10) ². (21) = 2100π

Volume of "hole" cylinder = π. (6) ².21 = 756π

Volume of metal needed = 2100π-756π = 1344π mm³