Well first things first I would convert the units from mixed fractions to improper fractions so they are easier to work with. Doing that we would get....
\(\frac{20}{3}\) pounds of walnuts
\(\frac{4}{3}\) pounds per container
Now that we've done that we can go back to determining how to solve the problem. There are 20/3 pounds of walnuts. To find out how many 4/3 lb contains, we would have to divide the pounds of walnuts (20/3 pounds) by the pounds per container (4/3 pounds):
\(\frac{\frac{20}{3}}{\frac{4}{3}} \)
Flip the denominator and multiply it by the numerator.
\(\frac{20}{3} * \frac{3}{4} = \frac{60}{12} \)
60/12 equal 5, so the answer would be that the walnuts fill 5 containers