Regents Earth Science worksheet featuring a world map with time zone calculations based on longitude.

Let’s solve this step by step.

We’re working with time zones. The key rule is:
- Every 15 degrees of longitude = 1 hour difference.
- Going east → time gets later (add hours).
- Going west → time gets earlier (subtract hours).

First, let’s find the longitude for each location from the map:

Location A: around 75°W
Location B: around 0° (Prime Meridian)
Location C: around 90°E
Location D: around 120°E
Location E: around 60°W
Location F: around 135°E
Location G: around 15°E
Location H: around 150°W

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Problem 1: If it is 9:00 a.m. in location A (75°W), what time is it elsewhere?

We’ll calculate how many hours different each place is from A (75°W).

→ Location E (60°W):
Difference = 75 - 60 = 15° → 1 hour
Since E is EAST of A → add 1 hour → 9:00 + 1 = 10:00 a.m.

→ Location B (0°):
Difference = 75 - 0 = 75° → 75 ÷ 15 = 5 hours
B is EAST of A → add 5 hours → 9:00 + 5 = 2:00 p.m.

→ Location C (90°E):
From 75°W to 90°E = 75 + 90 = 165° → 165 ÷ 15 = 11 hours
C is EAST of A → add 11 hours → 9:00 + 11 = 8:00 p.m.

→ Location G (15°E):
From 75°W to 15°E = 75 + 15 = 90° → 90 ÷ 15 = 6 hours
G is EAST of A → add 6 hours → 9:00 + 6 = 3:00 p.m.

✔ So for Problem 1:
E = 10:00 a.m.
B = 2:00 p.m.
C = 8:00 p.m.
G = 3:00 p.m.

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Problem 2: If it is 6:30 p.m. in location F (135°E), what time is it elsewhere?

F is at 135°E. We’ll compare others to F.

→ Location C (90°E):
Difference = 135 - 90 = 45° → 45 ÷ 15 = 3 hours
C is WEST of F → subtract 3 hours → 6:30 p.m. - 3 = 3:30 p.m.

→ Location E (60°W):
From 135°E to 60°W = 135 + 60 = 195° → 195 ÷ 15 = 13 hours
E is WEST of F → subtract 13 hours → 6:30 p.m. - 13 hours
6:30 p.m. minus 12 hours = 6:30 a.m., then minus 1 more = 5:30 a.m.

→ Location H (150°W):
From 135°E to 150°W = 135 + 150 = 285° → but we can go the shorter way around the globe!
Actually, total circle is 360°, so 360 - 285 = 75° the other way → 75 ÷ 15 = 5 hours
H is EAST of F if we go the short way? Wait — let’s think carefully.

Better approach: Convert both to same system.

F = 135°E
H = 150°W = -150° (if we use negative for west)

Difference = 135 - (-150) = 285° → too big. Instead, since Earth is round, smallest angle between them is min(285, 360-285) = min(285, 75) → 75°

Now direction: From F (135°E) to H (150°W), going west crosses Pacific → that’s 75° westward? Let’s check:

From 135°E → 180° = 45°
Then 180° to 150°W = 30° → total 75° west → yes.

So H is 75° WEST of F → 5 hours earlier → 6:30 p.m. - 5 hours = 1:30 p.m.

Wait — actually, 150°W is further west than 135°E? Yes, because 135°E is in Asia/Australia, 150°W is near Alaska/Hawaii — so yes, H is west of F.

But let’s double-check using another method:

Time zone for F (135°E) = UTC+9 (since 135÷15=9)
Time zone for H (150°W) = UTC-10 (since 150÷15=10, and west is negative)

Difference = 9 - (-10) = 19 hours? That can’t be right for local time difference.

Actually, when calculating time difference between two longitudes, we take the absolute difference modulo 360, then divide by 15, and assign sign based on direction.

Easier: Use the map grid.

Looking at the map:

F is at 135°E
H is at 150°W

Count the lines: from 135°E to 180° is 3 steps (each 15°) → 45°
From 180° to 150°W is 2 steps → 30°
Total = 75° → 5 hours

And since H is west of F → subtract 5 hours → 6:30 p.m. - 5 = 1:30 p.m.

Yes.

→ Location D (120°E):
F is 135°E, D is 120°E → difference = 15° → 1 hour
D is WEST of F → subtract 1 hour → 6:30 p.m. - 1 = 5:30 p.m.

✔ So for Problem 2:
C = 3:30 p.m.
E = 5:30 a.m.
H = 1:30 p.m.
D = 5:30 p.m.

Wait — let me recheck E again.

F = 135°E
E = 60°W

Total degrees apart: 135 + 60 = 195° → 195 ÷ 15 = 13 hours

Since E is west of F → subtract 13 hours from 6:30 p.m.

6:30 p.m. minus 12 hours = 6:30 a.m.
Minus 1 more hour = 5:30 a.m. → correct.

All good.

Final Answer:

1)
E: 10:00 a.m.
B: 2:00 p.m.
C: 8:00 p.m.
G: 3:00 p.m.

2)
C: 3:30 p.m.
E: 5:30 a.m.
H: 1:30 p.m.
D: 5:30 p.m.