Answer:
0 hamburgers
Explanation:
if the consumer's budget is $50 and each hamburger and cheese sandwich costs $5 each, her consumption possibilities frontier is:
hamburgers cheese sandwiches
10 0
9 1
8 2
7 3
6 4
5 5
4 6
3 7
2 8
1 9
0 10
Since she is spending all her money on cheese sandwiches, she doesn't have any money left to spend in hamburgers.