9514 1404 393
Answer:
297 miles
Step-by-step explanation:
The round-trip distance from X to Y is double the one-way distance. The distance from X to Y is 648/2 = 324 miles.
That distance is the sum of distances from X to Z and Z to Y. Then ...
XZ +ZY = XY
27 +ZY = 324
ZY = 297
It is 297 miles from City Z to City Y.
