Final answer:
Keith puts approximately 2.6 ounces of tuna on each sandwich.
Step-by-step explanation:
Keith has 7.8 ounces of tuna salad. To find out how much tuna he puts on each sandwich, we divide the total amount of tuna salad by the number of sandwiches. In this case, he makes 3 sandwiches, so we divide 7.8 ounces by 3 to get approximately 2.6 ounces of tuna on each sandwich