What is the smallest number of airplanes needed to ensure the complete flight of one plane around the world?

1 Answer (Check Answer ▼)

-Start three planes from the airport.
-After going 1/8 around, one plane refuels the other two with 1/4 of a tank each, leaving it with 1/4 of a tank which is precisely enough to take it home.
-Two planes continue with a full tank again.
-Reaching 1/4 around the other plane transfers 1/4 tank of fuel to yours, leaving it with 1/2 tank, to take it precisely home again.
-Your plane is now full at 1/4 and can go to 3/4 with that fuel.
-The first returning plane refuels and start off the other way meeting your plane at its 3/4 position, where your plane is empty and the meeting one is half empty. Sharing their fuel they have both 1/4 tank left which can take them to the 7/8 position.
-The remaining plane has arrived there in the meanwhile with 3/4 tank giving 1/4 to the other now empty planes.
-All three planes have now 1/4 and can return home.

answer Jul 16, 2019 by Hanifa Mammadov

Your answer

Preview

Email me at this address if my answer is selected or commented on:

Privacy: Your email address will only be used for sending these notifications.

Anti-spam verification:

To avoid this verification in future, please log in or register.

Similar Puzzles

0 votes

For at least one plane to finish a trip around the world, how many planes do you need at least?

There is an air base on the equator. The maximum amount of fuel that a plane can contain would be only sufficient for it to fly halfway around the world.

For at least one plane to finish a trip around the world, how many planes do you need at least?

Share your answer with detail explanation...

A trip around the world!
Logic Level 3

There is an air base on the equator. The maximum amount of fuel that a plane can contain would be only sufficient for it to fly halfway around the world.

For at least one plane to finish a trip around the world, how many planes do you need at least?

Details and assumptions:
Same plane doesn't depart twice or more.
The airplanes can use their fuel until it's empty. Starting the airplane doesn't take any time.
Every plane moves at the same speed, and on the same airway.
Assume the planes and air base are dimensionless, and thus, can turn directions instantly.
The plane can only be fueled via aerial refueling, and the amount of time the process takes is negligible.
Every plane starts at the air base and must return to the air base.

0 votes

What is the fewest number of airplanes and number of tanks of fuel needed to accomplish this work?

The puzzle question is : On Bagshot Island, there is an airport. The airport is the home-base of an unlimited number of identical airplanes. Each airplane has a fuel capacity to allow it to fly exactly 1/2 way around the world, along a great circle. The planes have the ability to refuel in flight without loss of speed or spillage of fuel. Though the fuel is unlimited, the island is the only source of fuel.
What is the fewest number of aircraft necessary to get one plane all the way around the world assuming that all of the aircraft must return safely to the airport? How did you get to your answer?
Notes:
(a) Each airplane must depart and return to the same airport, and that is the only airport they can land and refuel on ground.
(b) Each airplane must have enough fuel to return to airport.
(c) The time and fuel consumption of refueling can be ignored. (so we can also assume that one airplane can refuel more than one airplanes in air at the same time.)
(d) The amount of fuel airplanes carrying can be zero as long as the other airplane is refueling these airplanes.
What is the fewest number of airplanes and number of tanks of fuel needed to accomplish this work? (we only need airplane to go around the world)

0 votes

You have 32 numbers. What is the least number of comparison needed to find the 2nd smallest out of them?

+1 vote

What is the least number of comparison needed to find the 2nd smallest out of them?

You have 64 numbers. What is the least number of comparison needed to find the 2nd smallest out of them?

0 votes

I was taking a plane to China and almost missed my flight. On my way to the terminal there were 7 other girls walking...

I was taking a plane to China and almost missed my flight. On my way to the terminal there were 7 other girls walking in the opposite direction. Each of these girls had 8 purses and each purse had 2 dogs.

How many in all were on the plane?