Question

Towns X, Y, and Z are on the same straight road. Town Y is between Town X and Town Z. Town X is 57 miles from Town Z, and Town Y is 28 miles from Town Z. What is the distance from Town X to Town Y?

Answer 1

The distance between town X and Town Y is equal to the difference between the distance between Town X and Town Z and the distance from Town Y and Town Z. Mathematically
                      d (X-Y) = d (X-Z) - d(Y-Z)
Substituting,
                      d(X-Y) = 57 miles - 28 miles = 29 miles
Thus, the distance from Town X to Town Y is 29 miles. 

Answer 2

Towns X, Y, and Z are on the same straight road. Town Y is between Town X and Town Z. Town X is 57 miles from Town Z, and Town Y is 28 miles from Town Z.
Total distance=57 miles.
Subtract the distance from y to z
57 miles - 28 miles = 29 miles
Hence,
The distance from Town X to Town Y is 29 miles.
I hope it helps.
Thank you