 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 the set 369, 1215, 1821, B equals to the set 48, 1216, 20, C equals to the set 246, 810, 1214, 16 and D equals to the set 5, 10, 15, 20 then find the fourth part that is B minus A. Let us see the solution to this one. We see that B minus A is the set 48, 16 and 20. This is our answer to this question. I hope you understood the question and enjoyed the session. Have a good day.