Problem:
Let , and be five consecutive terms in an arithmetic sequence, and suppose that . Which of the following can be found?
Answer Choices:
A.
B.
C.
D.
E.
Solution:
Let be the difference between consecutive terms of the sequence. Then , and , so
Thus , so .
To see that the values of the other terms cannot be found, note that the sequences and both satisfy the given conditions.
The problems on this page are the property of the MAA's American Mathematics Competitions