Two events $E$ and $F$ are independent. If $P(E)=0.3$ and $P(E \cup F)=0.5$, then $P(E / F)-P(F / E)$ equals to

A bag contains 5 red and 3 blue balls. If 3 balls are drawn at random without replacement, them the probability of getting exactly one red ball is

Refer to question 74 above. If the probability that exactly two of the three balls were red, then the first ball being red, is

Three persons $A, B$ and $C$, fire at a target in turn, starting with $A$. Their probability of hitting the target are $0.4,0.3$ and 0.2 , respectively. The probability of two hits is

Assume that in a family, each child is equally likely to be a boy or a girl. A family with three children is chosen at random. The probability that the eldest child is a girl given that the family has atleast one girl is