PRE CAL. JOURNAL
posted by RAMATU .
A BAG CONTAINS 3 RED CHIPS, 2 BLUE CHIPS AND 1 WHITE CHIP. IF 2 CHIPS ARE CHOSEN FROM THE BAG WITHOUT REPLACEMENT DETERMINE THE PROBABILITY THAT THEY ARE OF DIFFERENT COLORS
You can calculate the different combinations to get different colours, but you can also calculate the probability P of getting the same colours, and the required probability is 1-P.
get two reds: (3/6)*(2/5)=1/5
get two blues: (2/6)*(1/6)=1/18
Probability of getting two reds or two blues: (1/5)+(1/18)=23/90
Probability of not getting two of the same colour = 1-(23/90)=67/90