Brain Teasers - Coins

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4.5k
Times solved
Intermediate
Difficulty
Rating

Problem Definition

Coins

Situation:
Imagine, we are sitting together at a perfectly round table. We both have an infinite pile of quarters. These are the rules of the game: “We'll take turns putting one quarter down on the table, no overlapping allowed, and the quarters must rest flat on the table surface. The first guy who can't put a quarter down loses."

Question:
Who should start in order to win, why and how does your strategy work?

Marbles

Situation:

There are 8 marbles that weigh 1 ounce each, and 1 marble that weighs 1.1 ounces. The marbles are all uniform in size, appearance, and shape. You have a balance that contains 2 trays. You are only able to use the scale 2 times.

Question:

How do you determine which marble is the heaviest using only the scale and marbles in 2 weighings.

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4.5k
Times solved
Intermediate
Difficulty
Do you have questions on this case? Ask our community!