Math

posted by .

For the three-letter set {R, S, T}, find the two-letter combinations.

I realize that this deals with combinations and not permutations. I just do not understand how they want this done.

  • Math -

    you want 2 letters at a time, order not important

    so
    RS
    RT
    ST

    there are only 3 cases
    in combination notation
    C(3,2) = 3!/(2!1!) = 6/2 = 3

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Finite Math

    Please help with this problem. In a student writing contest with 25 entries, 3 essays are selected for first, second, and third place awards and 5 are selected for honorable mention. How many ways can this be done?
  2. Math: Permutations and Combinations

    Need a verification: Combinations of n items taken r at a time: C9n,r)= n!/(n-r)!*r! C(8,0) 8!/(8-0)!*(0)! = 8!/8!*0! = 0 or Answer is 0 or 1?
  3. 8th grade Math

    Penelope created a game using a bag of 26 tiles, each with a different letter of the alphabet written on it. She uses a stopwatch to time how fast she can create one 5-letter word from a set of five randomly selected letters. To play …
  4. Math/ Algebra 2

    How many different ways can the letters in the word COMBINATIONS be arranged if the letter C is first and the letter S is last?
  5. Math

    Hi! Can someone check my answers? Thanks!! Directions: Tell whether the following questions are either permutations or combinations. 1.) Number of ways the Junior class can elect a committee of officers - President, Vice President,
  6. Math

    Hi! Can someone check my answers? Thanks!! Directions: Tell whether the following questions are either permutations or combinations. 1.) Number of ways the Junior class can elect a committee of officers - President, Vice President,
  7. maths

    simplify 8C5 The "C" stands for combinations ( like combinations and permutations )
  8. statistics

    15. The probability that a recently offered stock by a technology company will double in value within the next three months is 90%. The conclusion regarding this probability estimate was reached based on the opinion of the experts …
  9. Math

    Allie and Betty want to know how many 3-letter combinations, such as BMW or DDT, are possible. (Letters are allowed to repeat, as in DDT or BOB.) Allie thinks there can be 26+26+26 three-letter combinations, whereas Betty thinks the …
  10. Math

    How many three-letter combinations are possible using the letters D, E, F, G, and H?

More Similar Questions