 Hello and welcome to the session. My name is Mansi and I am going to help you with the following question. The question says if A equals to 3, 6, 9, 12, 15, 18, 21, this set B equals to the set 4, 8, 12, 16, 20, C equals to the set consisting of 2, 4, 6, 8, 10, 14, 16 and D equals to the set 5, 10, 15 and 20, then find first A minus B. Let us see the solution to this one. It is given to us that A equals to the set 3, 6, 9, 12, 15, 18 and 21, B equals to the set 4, 8, 12, 16, 20. Therefore A minus B becomes the set 3, 6, 9. Now 12 is there in the set A, it is also there in the set B, so this gets cancelled. Now we have 15, 18 and 21. This is our answer to this question. I hope you understood the question and enjoyed the session. Have a good day.