Question

he following table shows the time in various cities when it is 4:00 a.m. in New York.

New York
4:00 a.m.
San Juan
5:00 a.m.
Buenos Aires
6:00 a.m.
Dublin
9:00 a.m.
Rome
10:00 a.m.
Istanbul
11:00 a.m.
Saint Petersburg
12:00 p.m.
Beijing
5:00 p.m.
Osaka
6:00 p.m.

If a flight between two of these cities leaves at 1:30 p.m. on Friday (local time), flies for 16 hours and 30 minutes, and arrives at 2:00 a.m. Saturday (local time), which of the following pairs of cities could the flight go between?
a.
New York and Rome
b.
Saint Petersburg and Beijing
c.
Dublin and San Juan
d.
Osaka and Istanbul

Answer 1

If the flight left at 1:30 p.m. Friday and flew 16.5 hours, in the same time zone it would arrive at 6:00 a.m. Saturday. Since it actually arrives at 2:00 a.m. Saturday, the arrival city's clock is 4 hours behind the departure city's clock.

From the table (offsets relative to New York): Dublin +5, San Juan +1. San Juan − Dublin = 1 − 5 = −4 hours, so a flight from Dublin to San Juan fits.

Answer: c.