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The Tide (medium)

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By Fred

Question: At low tide 14 rungs of a ship are above the water, the rungs are 15 centimeters apart. each 15 mins the water rises 15 centimeters. after 2 hours and 30 mins how many rungs are above the water?

Answer: 14

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3 coins (medium)

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Question: You have three coins. One always comes up heads, one always comes up tails, and one is just a regular coin (has equal change of heads or tails). If you pick one of the coins randomly and flip it twice and get heads twice, what is the chance of flipping heads again?

Answer: 90 percent. If you pick the heads coin the chance of getting the first 2 heads is 100 percent (4/4) and if you pick the fair coin the chance is 25 percent (1/4). So from this, the chance that it is the heads coin is 4/5 and the fair coin 1/5.

Then, if it is the heads coin you will definitely get heads (4/5). If you flip the fair coin it is 1/10 (1/5 * 1/2). Add the probabilities together: 4/5 + 1/10 = 9/10.

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By TheAsian1

Question: When is... 5>0, 0>2 and 2>5? Hint: Hands

Answer: Rock Paper Scissors

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Question: There are three jars full of equal amounts quarters, dimes, and penny's. Which one has the highest value?

Answer: The jar full of quarters would have the highest value because a quarter is worth more than a dime and penny. Amount refers to quantity, so if they have equal amounts there will be an equal number of each.

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By roxanelaster80

Question: Can you find the missing number in the below series? 43, 8, 38, 9, 34, 11, _, 14

Answer: One series is 8, 9, 11, 14 (add 1, 2, 3) and the second series is 43, 38, 34, ? (subtract 5, 4 - next number to substract is 3). Correct answer is 31

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