If we want to know the total amount of pounds of donuts, we firstly have to make a sum of each element Beulah used to make her donuts:

where D is the total pounds of donuts made.
In order to solve this, we have to take the Lowest Common Denominator, this means that we have to multiply de denominators to obtain a common denominator, in this case the value is:

this is the common denominator now. Then we have to divide this value by each denominator and then multiply the result with each numerator, as follows:

with the following result:

This is D, the total pounds of donuts made.
Now, we need to express this as a mixed-number, in this case we have to:
- divide 121 by 60 and input the number part result
- then in the numerator of the fraction we input the reminder of the divission
- finally input the denominator
having the final result:
