Question 329192
This is like a d=rt ptoblem, only with cashews instead of cars, planes, boats, etc.

Let r=Casey's rate. Then David's rate is r+3.

Since their times are equal, we have:

{{{80/(r+3)=56/r}}}

{{{r=7}}}

Casey eats 7 per minute and, therefore, David eats 10 per minute.