Math

posted by .

Sam rolls a standard die, and then Ruth rolls the same die. The probability that Ruth's number is higher than Sam's can be written as a/b where a and b have no common factors greater than 1. Find a.

  • Math -

    There are six numbers, 36 boxes below
    * 1 2 3 4 5 6 Sam
    1
    2 *
    3 * *
    4 * * *
    5 * * * *
    6 * * * * *
    Ruth
    (5 + 4 + 3 + 2 +1)/36 = 15/36 = 5/12

  • Math -

    5. The probability that both Sam’s
    and Ruth’s roll produce the same result
    is 1/6. The likelihood that Ruth has the
    higher number is the same as the likelihood that Sam has the higher number.
    Thus, we divide the remaining 5/6 in
    half to get 5/12; the numerator is 5.

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Discrete Math

    You are stranded on a deserted island, and along the way you stumble across a genie. He says he will get you off the island provided that you can meet his conditions. He hands you a 20-sided die, and says that you need to roll it 1000000 …
  2. Math

    A die is rolled twice. What is the probability that the sum of the rolls is less than 4 given that one of the rolls is a 1?
  3. Probability

    The newest invention is a three-sided die. On any roll of this die, the result is 1 with probability 1/2, 2 with probability 1/4, and 3 with probability 1/4. Consider a sequence of six independent rolls of this die. 1. Find the probability …
  4. probability

    Consider n independent rolls of a k-sided fair die with k≥2: the sides of the die are labelled 1,2,…,k and each side has probability 1/k of facing up after a roll. Let the random variable Xi denote the number of rolls that …
  5. Maths

    Cam and Dean are playing a game with counters and dice. Cam has some counters, each labelled 1 on one side and 2 on the other. He flips the counters and scores the total of all the numbers showing. Dean has one die and scores the number …
  6. Probability

    The newest invention of the 6.041x staff is a three-sided die. On any roll of this die, the result is 1 with probability 1/2, 2 with probability 1/4, and 3 with probability 1/4. Consider a sequence of six independent rolls of this …
  7. Math

    Sam rolls a strike in 6 of the 10 frames of bowling What is the experimental probability that Sam will roll a strike in the first frame of the next game ?
  8. Algebra 2/statistics

    On a fair 6-sided die, each number has an equal probability p of being rolled. when a fair die is rolled n times, the most likely outcome (the mean) is that each number will be rolled NP times, with a standard deviation of sqrt NP(1-P). …
  9. Math

    Sarah rolls a die twice. What is the probability that she rolls a 3 and then an even number?
  10. Math work

    Sam makes some read rolls. He gives 2/5 of the bread rolls to his neighbor and 4/9 of the remainder to his cousin. He has 15 bread rolls left. How many bread rolls does Sam make?

More Similar Questions