Logicl Puzzle Questions

You are given a 3ltr and a 5ltr container. How can you measure 4 ltr?

You are given two containers, 50 red balls and 50 blue balls. Distribute these in a way such that the probability of picking a red ball is more/maximum.

You have five pieces of chain, each consisting of three links. You want to make one long chain of these five pieces. Breaking open a link costs 1 dollar, and welding an open link costs 3 dollars.

Is it possible to make one long chain of the five pieces, if you have just 15 dollars?

Stephanie has bought ten trees for her garden. She wants to plant these trees in five rows, with four trees in each row.
How must Stephanie plant the trees?

The king’s only children, Abel, Benjamin and Paula, went into the forest with their friend, the elderly Sir Kay. They wanted to try their skill with their bows and arrows. Each of them started with same number of arrows.
When all the arrows had been shot, it was discovered that:

1. Sir Kay brought down more game than Princess Paula.
2. Prince Benjamin captured more than Sir Kay.
3. Princess Paula’s arrows went truer than Prince Abel’s.

Who was the best marksman that day?

On door A - It leads to freedom

On door B - It leads to Ghost house

On door C - door B leads to Ghost house

The statement written on one of the doors is wrong. Identify which door leads to freedom

On Bagshot Island, there is an airport. The airport is the homebase 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).