Problem: The check for a luncheon of sandwiches, cups of coffee and one piece of pie came to . The check for a luncheon consisting of sandwiches, cups of coffee and one piece of pie came to at the same place. The cost of a luncheon consisting of one sandwich, one cup of coffee and one piece of pie at the same place will come to
Answer Choices:
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E.
Solution:
Let , and denote cost in dollars of sandwich, cup of collee, and piece of pie respectively, Then and . Subtracting twice the second of these two equations trom three times the first gives so that is the required cost.