Question

What is the longitude of a place where the local time 1:15 p.m. when it is 4 a.m. at Chicago (88°W)?

Answer 1

The time difference between the two places is 9 hours and 15 minutes or 540 + 15 = 555 minutes. So the longitudinal difference will be 555/4 = 138.75° degrees. So the longitude of the required place will be 50.75° or 50°45′E i.e. it will cover 88° from west to 0° and 50°45' east from 0° or Greenwich line.