Okay, for variable B you have the data points:
1, 2, 3, 5, 6, 6, 7, 7, 10, and 10.
What you need to do to find the mean (or average) is add all the data up and divide by how many pieces of data you had. So, the sum of all the points is 57. There are 10 points overall.
57/10 is 5.7
Your average for variable B is 5.7