probability
posted by karlo on .
there are 4 white balls and 6 red balls in a sack. If two balls are taken out successively ( the first ball is not replaced ) what is the probability that the balls are drawn are of different colors?

pr= prob second white given first red, plus prob second red given first white.
pr= 4/9*6/10 + 6/9*4/10= 48/90 
A box contains 10 balls of which 6 are red (R) and 4 are white (W) . Three balls are taken from the box at random, one after the other. The probability that the 3 balls drawn are in the order RRW is equal to,

xdf_ghdf

tommy has 7 yellows 6 green 3 blues 8 red wht it tommy probability that she will not draw a green ball