Question

An urn contains 6 yellow, 5 blue and 2 white marbles. If three marbles are picked at random, what is the probability that at least one is blue?​
a)115/199
b)115/143
c)28/197
d)28/143

Answer 1

Answer:

115/143

Step-by-step explanation:

An urn contains 6 yellow, 5 blue and 2 white marbles. If three marbles are picked at random, what is the probability that at least one is blue?​  

a)115/199

b)115/143  

c)28/197  

d)28/143

We will find out probability of no blue balls

and reduce it from 1 to get  the probability that at least one is blue

Probability of no blue balls :

Total Balls 13 , non-Blue Balls = 8

After selecting 1st non-blue ball Total Balls 12 , non-Blue Balls = 7

in last selection  Total Balls 11 , non-Blue Balls = 6

Probability of no blue balls : = (8/13)(7/12)(6/11)

= 8 * 7 * 6 /( 13 * 12 * 11)

= 28/143

the probability that at least one is blue = 1 - 28/143

= 115/143

Answer 2

Answer:

115/143

Step-by-step explanation:

is the ans for about question