Here's one way: First, look for a common denominator such as 12. Next, you do 3 1/3 x 4 giving you 3 4/12 and 2 3/4 x 3 giving you 2 9/12. Now change the newly changed mixed numbers into improper fractions because 2 9/12 has a greater numerator than 3 4/12 so...3 4/12 becomes 40/12 and 2 9/12 becomes 33/12. Then you subtract 40/12 and 33/12 to get 7/12 as your final result.