Question

An urn contains eight blue balls and seven yellow balls. if six balls are selected randomly without being​ replaced, what is the probability that of the balls​ selected, two of them will be blue and four of them will be​ yellow

Answer 1

to be sure that 2 of them will be blue i have to select 7+2=9 balls
7+8=15 balls in the urn
P=9/15

to be sure that 4 of them will be yellow i have to select 8+4=12 balls
P=12/15