Question 1128813
Determine number of lead balls, 1/4 in. in diameter, are in 1 lb.

Lead weighs .41 lbs. per cu. in.
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0.25 d = 0.125 radius
{{{Vol = 4pi*r^3/3 = 4pi*(1/8)^3/3 = 4pi/(3*512) = pi/384}}} cubic inches per ball.
Mass = Vol*density = (pi/384)*0.41 pounds pounds/ball
balls/pound is the inverse of pounds/ball = 384/(0.41*pi)
=~ 298 balls/pound