three numbers are chosen at random without replacement from a set containing elements 1,2,3,4,5,6,7,8.probability that there minimum is 3,given that there maximum is 6,is

Let 

P(A)=Probability that 3 is min

P(B)=Probability that 6 is max

To find is P(A/B)

P(A/B) = P(A∩B)/P(B)

Now

P(B) = 5C2/8C3 

P(A∩B) = 2C1/8C3

now P(A/B) = 2C1/5C2 =2/10 = 1/5

this is the required probability