Question 1154027
P(red) = (# of red) / (total # of balls) =  4/(4+6+5) = {{{ highlight( 4/15 ) }}}

P(not yellow) = P(red or green) / (total #) = (4+6)/(4+6+5) = 10/15 = {{{ highlight(2/3)}}}  --OR--  you can say P(not yellow) = 1 - P(yellow) = 1 - (5/15) = 10/15 = 2/3