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This problem trains for: SAT-I, AMC-8, GMAT.

Three distinct numbers a, b, c are in arithmetic progression. If:

then which one of the following statements about the ordering of the numbers is true?

Since the numbers are all different, equality between any two of them is not possible.

Therefore, we can write the absolute values as follows:

There are 4 possible ways of ordering the three numbers. Two of them are impossible to fulfill:

The other two yield the same value for b:

But for an arithmetic progression this is always true if b is the term 'between' a and c.