Answer:
12 bags
Step-by-step explanation:
If the total weight was 160 pounds and each bag weighs 40/3 pounds, we need to divide the total weight between the weight of each bag in order to know how much each bag weights.
[tex]\frac{160}{\frac{40}{3} } =\frac{(160)(3)}{40} =\frac{480}{40} = 12[/tex]
Therefore, the total number of bags of grain that Robin donated is 12.