24 3-pound bags(72 pounds) and 10 5-pound bags(50 pounds). 72+50 = 122 pounds, 24+10 bags = 34 bags.
1. You have the function 
2. You know that
with
, because the division by zero is not defined. So ,
for
where
is a integer number.
3. Then, to find the domain of the function given in the problem, you must make 
Where
is odd number.
4. Therefore:

5. Finally, the domain is: 
The answer is: 
180
Because 120 divided by 2 is 60.
And 120 + 60 is 180