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BMAD last won the day on August 31 2017

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About BMAD

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  • Birthday 02/26/1980

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  1. If the antiderivative of u^-1 = ln |u| + c then why does this not follow: integrate 1/(2x) dx set u =2x, then du = 2 dx, then dx = (1/2)du Then we could integrate (1/2)(1/u)du By the definition above we get 1/2 ln|u| + c which means that the integration of 1/(2x) = 1/2 ln|2x|| + c However, this is a false statement.
  2. there is a faster time
  3. 5 college students need to cross a river in a small boat. Two of these students are on the rowing team and can cross it in one minute if either one or both are rowing. The other three are not and will take four minutes to cross even if they are with the rowing team members. The boat can only hold up to three people at a time. What is the shortest amount of time it will take to cross the river?
  4. A thin four-foot long chain is suspended by its ends and nailed to a wall. Both nails are level with one another and parallel to the floor. Because of gravity, the middle of the chain is hangs down towards the floor. If the vertical length of the chain is two feet, what is the distance between the nails?
  5. Soldiers in a field

    An odd number of soldiers are stationed in a field such that all the pairwise distances are distinct. Each soldier is told to keep an eye on the nearest other soldier. Prove that at least one soldier is not being watched.
  6. Who can go the lowest?

    Each person is betting $10 that they can pick the lowest positive integer that is not picked by anyone else. Each time an individual chooses a number they bet $10. Once everyone is satisfied that they picked enough numbers (as they can pick more than one) they show their choices. The individual with the lowest number that was not picked by anyone else, wins $100. You are competing against nine other logical and equally wealthy people, what would be your strategy to win the prize?
  7. How many squares?

    how are we defining touching?
  8. Suppose you have a point within a equilateral triangle. If you were to connect each vertex to this point you would make three new line segments. Assume that you knew two of the angles formed at the point. Build a triangle out of these line segments. What can the two known angles tell us about the angles of this newly created triangle.
  9. Stefan borrowed a watch from his friend ,returned home and set his grandfather clock to the correct time

  10. The clock setter

    Stefan was on his way out the door to visit an old friend across the village when he realized that his grandfather clock had stopped and no longer displayed the correct time. This was the only clock in his home and the man owned no watches or other time-telling devices. Without disappointment Stefan left his home and walked roughly three miles to his friend's house. He glanced at the friend's wall clock as he entered the house and after visiting for a few hours set off back home along the same route. He walked at the same pace home and had no idea of knowing how long his trip back took him. Regardless, when Stefan got back home he immediately went to his grandfather clock and set it to the correct time. How did he know what time it was?
  11. Flocks of ducks

    There was a flock of ducks flying in the sky. One ahead of the other two; one behind of the other two; one between the other two, and three in a row. How many ducks were flying?
  12. The halfway glass

    I know what you mean but I don't think it is worded it right
  13. Bill sold his motor scooter to Tom for $100. After driving it around for a few days Tom discovered it was in such a broken-down condition that he sold it back to Bill for $80. The next day Bill sold it to Herman for $90. What is Bill's total profit?
  14. You and two of your friends would like to know the average of all of your salaries. You are each self-conscious about the amount of money you make and will not tell one another your salaries. What can you do to figure out the average salary?