If your ground speed is 120 knots and you want to cover 60 nautical miles, how long will it take?

• A. 0.25 hours
• B. 0.5 hours
• C. 1 hour
• D. 2 hours

Answer: (B)

Time equals distance divided by speed. With a ground speed of 120 knots, you cover 120 nautical miles in one hour. To travel 60 nautical miles, you need half an hour. So the time is 60 ÷ 120 = 0.5 hours, which is 30 minutes. The other values would imply different distances at the same speed or the same distance at different speeds: 0.25 hours would require a faster speed (240 knots) to cover 60 nm; 1 hour would cover 120 nm at this speed; 2 hours would cover 240 nm.