 Hello and welcome to the session. In this session, we shall discuss the following question and the question says that Mrs. and Mr. Smith have three children. List the sample space of the possible orders of three children being a boy or a girl child. What is the probability of having at least one girl? We know that sample space is a complete list of all possible outcomes of a random experiment. This is also called as possibility space and it is denoted by capital F. With this key idea, let us proceed to the solution. In this question, we are given Mrs. and Mr. Smith have three children and we need to list the sample space of the possible orders of three children being a boy or a girl child. And we also need to find the probability of having at least one girl. So first, we list the elements of sample space and then find the probability here. Let B denotes the boy child and G denotes the girl child. Now Mrs. and Mr. Smith have three children, maybe all boys or two boys and one girl, one boy and two girls or it could be all girls. Now from the key idea, we know that sample space is the complete list of all possible outcomes of a random experiment. So here, all possible outcomes are given by S is equal to the set containing elements that is B, B, B or boys or two boys and one girl. That is, it can be in any of the three forms boy, boy, girl or boy, girl, boy or girl, boy, boy. Next we have one boy and two girls and this also can be in any of the three forms that is boy, girl, girl, girl, boy, girl. And all we have girl, girl and a boy and next is all girls that is girl, girl and girl. So we see that there are eight possible outcomes. Next we need to find the probability of having at least one girl. So let event A be equal to having at least one girl. It means it can have minimum one or more than one girl. And favorable outcomes from sample space will be all the outcomes that favor the event of having one or more than one girl. So event A will be equal to the set containing elements that contains at least one girl and we get boy, boy, boy, boy, boy, boy, boy, boy, boy, boy, boy, boy. Here we see that seven outcomes are in favor of event A, so probability of event A denoted by P of event A will be given by favorable outcomes divided by total outcomes and here we see that number of favorable outcomes is seven and the number of total outcomes is eight. And thus we get the probability of event A as seven upon eight which is the required answer. This completes our session, hope you enjoyed this session.