A consumer is consuming at a point on her budget line. Her income is $50 a week, and she purchases hamburgers and grilled cheese sandwiches. Both goods cost $5 each, and she consumes 10 grilled cheese sandwiches. How many hamburgers does she consume?

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.