PLEASE HELP ASAP PLEASE I DON'T UNDERSTAND THIS

A. (1 and 1), (1 and 2), (1 and 3), (1 and 4), (1 and 5), (1 and 6), (2 and 2), (2 and 3), (2 and 4), (2 and 5), (2 and 6), (3 and 3), (3 and 4), (3 and 5), (3 and 6), (4 and 4), (4 and 5), (4 and 6), (5 and 5), (5 and 6), and (6 and 6).

B. 6/21

C. Supposed you rolled the two number cubes 100 times, you would expect at least one 4 less than 34 times because the chance of rolling a 4 is low.