 Hi and welcome to this session. I am Asha and I am going to help you with the following question which says let A be a set containing elements A and B and B is a set which contains elements A, B and C is A is subset of B and what is A union B? So first let us learn some key concepts with the help of which we will solve the above problem. First is the simple denotes that is if we write like this, this means A is a subset of B and this symbol denotes union of sets. If every element of a set A is also an element of a set B then A is called a subset of set B that is A is a subset of B implies every element of A is also an element of set B and the union of two sets A and B that means all those elements X such that X is either an A or in B or in both. So these are some ideas which we are going to use in this problem to solve it. So these are key ideas. Let us now start with the solution is the set containing elements A and B and B is the set containing elements A, B and C. Now as we can see every element of A is also an element of B so A is contained in B that is A is a subset of B also all elements which are either in A or in B or in both are A, B and C and hence A union B is equal to A, B and C. So our answers are first we ask whether A is a subset of B or not. Yes, A is a subset of B and second both is A union B so A union B is a set of elements A, B and C. So this completes the solution hope you enjoyed it take care and have a good day.