A cylindrical quarter has a 15/16 inch diameter and a 1/16 inch height. What would be the number of inches in the height of a coin whose volume is exactly four times that of the given quarter and whose diameter equals 1 1/8 inches? Express your answer as a common fraction.

Guest Jun 5, 2018

#1**+2 **

Volume of the quarter = pi r^2 x h

= pi * (15/16 * 1/2)^2 * 1/16

FOUR times this volume is (the new coin volume)

4 * pi * (15/16 * 1/2)^2 * 1/16

the new coin volume = pi r^2 h also

pi * (9/8 * 1/2)^2 h = 4 * pi * (15/16 * 1/2)^2 * 1/16 solve for the new coin's h

(9/16)^2 h = 1/4 (15/32)^2

h= 25/144

ElectricPavlov
Jun 5, 2018