Question 1184405
ASSUMING that the values of 29.5 and 30 you mentioned in your question are actually 29.5 inches and 30 inches, 
respectively, then from the given,


{{{30 >= C >= 29.5}}},  where C is the circumference of the ball.

<===> {{{30 >= pi*D >= 29.5}}}, where D is the diameter of a ball.

<===> {{{30/pi >= D >= 29.5/pi}}}.  

===> {{{60/pi >= 2D >= 59/pi}}}, or {{{19.0986 >= 2D >= 18.78}}}.


Therefore two identical basketballs getting into the hoop side-by-side won't be possible.