If an aircraft cruises at 300 mph and experiences a tailwind of 35 mph, what is its ground speed?

• A. 335 mph
• B. 300 mph
• C. 270 mph
• D. 325 mph

Answer: (A)

Ground speed is the speed over the ground, which combines the aircraft’s airspeed with any wind along the flight path. When you have a tailwind, it adds to the airspeed.

Here, the airplane flies at 300 mph through the air, and a tailwind of 35 mph pushes it forward, so the ground speed becomes 300 + 35 = 335 mph. That’s why 335 mph is the best answer.

The other numbers don’t fit the given situation: without wind the ground speed would be 300 mph, not affected by wind. A value like 270 mph would require a headwind of 30 mph (subtracting wind instead of adding). A result of 325 mph would correspond to a tailwind of 25 mph, which isn’t the case here.