from __future__ import division, print_function
import random
balls = [ 'R' , 'R' , 'R' , 'B' ]
two_red = 0
one_red = 0
for i in xrange ( 10000 ) :
balls_taken = random .sample ( balls, 2 )
looked_at = random .choice ( balls_taken)
if looked_at == 'B' :
continue
elif balls_taken.count ( 'R' ) == 2 :
two_red += 1
else :
one_red += 1
print ( 'Times we took two red and looked at a red ball:' , two_red)
print ( 'Times we took one red and looked at a red ball:' , one_red)
print ( 'Probability the other ball is red:' , two_red / ( one_red + two_red) )
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