Sunday, February 6, 2011

Problems of the Week 2/7

Please review the solutions to the previous week's set. Then, move onto this one. In the meantime, be looking at the marathon problems.

1. Laws in certain states require a 60% approval rate from voters before issues are “passed”. If 1,140 people voted in favor of the law, and this represents 57% of the total number of voters, how many voters were there in this election?

2. Two congruent cones with radius 12cm and height 12cm are enclosed within a cylinder. The base of each cone is a base of the cylinder, and the height of the cylinder is 24cm. What is the number of cubic centimeters in the volume of the cylinder not occupied by the cones? Express your answer in terms of π.

3. The sum of three different prime numbers is 40. Find the product of the largest two of the primes.

4. Shauna did a number trick with Zach. She told him to pick an even number, double it, add 48, divide by 4, subtract 7, multiply by 2, and subtract his original number. She then told him the result he should have attained. What was it?

5. A positive three digit integer is divided by a positive two digit integer, yielding an integer quotient and zero remainder. What is the smallest possible integer quotient?

Have fun, guys!

20 comments:

  1. Vishal's problem is posted on the marathon. Please take part in it! :-)

    ReplyDelete
  2. 1) 2,000
    2) 2304π...not so sure
    3) 155
    4) 10 not so sure
    5) 2

    ReplyDelete
  3. Vishal, don't doubt your work :-) Keep trying problem 3.

    Since most of the answers are kind of revealed... Everyone, please support each of your answers with a brief description of your approach to the problem.

    Thanks and have fun!

    ReplyDelete
  4. Correct!

    Since no one else has replied yet, would you like me to post a few more problems for you?

    ReplyDelete
  5. Practice: Permutations

    1. You are ranking your elective class choices for the upcoming school year. You must rank your top 5 selections in order of preference. How many ways can you rank 5 of the 7 electives that interest you?

    2. For the pick 3 lottery, six balls numbered 1 through 6 are placed in a hopper and randomly selected one at a time without replacement to create a three-digit number. How many different three-digit numbers can be created?

    3. Find the number of arrangements of the letters in the word BOOKKEEPER.

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  6. 1) 35

    Working on the others

    ReplyDelete
  7. Keep working on the first one, Vishal. I'm glad the problems are giving you a challenge :-)

    If you need any hints, let me know.

    ReplyDelete
  8. Okay, I will give you a hint for the first one.

    How many choices do you have for your top pick? Your second pick? Your third pick? And so on?

    ___ × ___ × ___ × ___ × ___ = Answer

    first
    pick

    ReplyDelete
  9. Permutations:

    A permutation is an arrangement in which order matters.

    Example: Five students are running a race. In how many ways can the three of five students place 1st, 2nd, and 3rd?

    Reasoning: 5 students can win, leaving 4 who can place second and then 3 for third place. This makes 5 × 4 × 3 = 60 ways that students can place 1st, 2nd, and 3rd.

    ReplyDelete
  10. Yay! You got it now! Go ahead and try the others.

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  11. Why aren't we getting more problems? Hello?

    --
    Maya E.

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  12. 3)362880....I don't think this is right...

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  13. Sorry, I haven't been on the blog, Agni. I've been kind of busy. Could you please clarify my doubts on this factorial problem?

    13!

    Mrs.Cherry said it was 13 or 12, but I think I misunderstood her. I got the answer as 6 227 020 800. Is that right?

    ReplyDelete