Tag: math & puzzles

Questions Related to math & puzzles

Thirty men take 20 days to complete a job working 9 hours a day.How many hour a day should 40 men work to complete the job?

  1. 8

  2. 7 1/2

  3. 7

  4. 9


Correct Option: B

Using the digits 1 up to 9, two numbers must be made. The product of these two numbers should be as large as possible. All digits must be used exactly once. The Question: Which are the requested two numbers?

  1. 9642, 87531

  2. 9753, 86421

  3. 98756, 4321

  4. 97531, 8642


Correct Option: A

AI Explanation

To maximize the product of two numbers formed using the digits 1 to 9, we need to consider the place value of each digit.

Let's analyze each option:

A. 9642, 87531 The larger number, 87531, is formed by placing the larger digits in the higher place values. This arrangement maximizes the product.

B. 9753, 86421 In this option, the larger number, 86421, has a smaller digit, 6, in the highest place value compared to option A. Therefore, the product will be smaller than option A.

C. 98756, 4321 The larger number, 98756, is formed by placing the larger digits in the higher place values. However, the smaller number, 4321, has the smaller digits in the higher place values compared to option A. Therefore, the product will be smaller than option A.

D. 97531, 8642 In this option, the larger number, 97531, is formed by placing the larger digits in the higher place values. However, the smaller number, 8642, has a smaller digit, 6, in the highest place value compared to option A. Therefore, the product will be smaller than option A.

Therefore, the correct answer is A, where the two numbers are 9642 and 87531.

Three friends Pablo, Edvard, and Henri are talking to each other about the art collection of Leonardo. Pablo says: "Leonardo has at least four paintings of Rembrandt." Edvard says: "No, he has less than four paintings of Rembrandt." "According me," says Henri, "Leonardo has at least one Rembrandt." The Question: If you known that only one of the three friends is right, how many Rembrandts does Leonardo possess?

  1. 0

  2. 1/2/3

  3. 4

  4. > 4


Correct Option: A

Richard is a strange liar. He lies on six days of the week, but on the seventh day he always tells the truth. He made the following statements on three successive days: Day 1: "I lie on Monday and Tuesday." Day 2: "Today, it's Thursday, Saturday, or Sunday." Day 3: "I lie on Wednesday and Friday." The Question: On which day does Richard tell the truth?

  1. Sunday

  2. Monday

  3. Friday

  4. Tuesday

  5. Thursday


Correct Option: D

AI Explanation

To answer this question, let's analyze each statement made by Richard on three successive days:

Day 1: "I lie on Monday and Tuesday." This statement means that Richard is lying on Monday and Tuesday. Since Richard lies on six days of the week, this statement is consistent with his lying behavior.

Day 2: "Today, it's Thursday, Saturday, or Sunday." This statement is a bit tricky. If Richard is telling the truth, then it must be either Thursday, Saturday, or Sunday. However, since Richard only tells the truth on the seventh day, this statement is inconsistent with his lying behavior. Therefore, Richard is lying on Day 2.

Day 3: "I lie on Wednesday and Friday." This statement means that Richard is lying on Wednesday and Friday. Since Richard lies on six days of the week, this statement is consistent with his lying behavior.

Based on the statements made by Richard, we can conclude that Richard tells the truth on the day after the second lie. Since Richard lied on Day 2, the day after the second lie is Day 3. Therefore, Richard tells the truth on Tuesday.

The correct answer is D) Tuesday.

On an early morning, three rivals get together on an open spot in a dark wood to compose a quarrel by means of guns. A kind of duel, but with three persons: A, B and C. The rules of the game are: They draw lots who may fire first, second and third. Next, they will continue firing at each other in this order until only a single person is alive. Every person decides himself at which person he fires. Everyone knows that A hits (kills) in 100% of all shots, B hits (kills) in 80% of all shots and C hits (kills) in 50% of all shots. Each person chooses his ideal strategy. No one is killed by a stray bullet. The Question: Who has the largest chance of surviving the truel, and how big is this chance?

  1. A, > 80%

  2. B, > 50%

  3. C, > 50%

  4. A, > 50%

  5. B, > 30%


Correct Option: C