Probability Combination and Permutation

When do we use the formula "nPr"?

• Permutation. All objects distinct
• Permutation. Some identical objects
• Arranging people in a row
• Forming a group of r objects

I want to arrange 5 people in a row out of a class of 10 people. Number of ways =

• 10P5

• 10C5

• 10!/(5-2!)

• 10!-5!

I want to arrange the letters A,A,A,B,B,C,D,E in a row with same alphabets together. Which of the following is the working for the number of arrangements?

• 5!*3!*2!

• 8!/(3!*2!)

• 8!

• 5!

Permutation or Combination: The student body of 30 students wants to elect a president, vice president, secretary, and treasurer.

• permutation

• combination

Tags

CCSS.HSS.CP.B.9

Permutation or Combination: Rob and Micaela are planning trips to four countries this year. There are 5 countries they would like to visit. One trip will be one week long, another two days, another two weeks, and the other a month.

• permutation

• combination

Tags

CCSS.HSS.CP.B.9

Permutation or Combination: A group of 40 people are going to run a race. The top three runners earn gold, silver, and bronze medals.

• permutation

• combination

Tags

CCSS.HSS.CP.B.9

Permutation or Combination: A group of 14 people need to take an elevator to the top floor. They will go in groups of seven. They are deciding who will take the elevator on its second trip.

• permutation

• combination

Tags

CCSS.HSS.CP.B.9

Permutation or Combination: You are setting the combination on a four-digit lock. You want to use the numbers 3817 but don't care what order they are in.

• permutation

• combination

Tags

CCSS.HSS.CP.B.9

Permutation or Combination: Jaidee and Amy are planning trips to four countries this year. There are 6 countries they would like to visit. They are deciding which countries to skip.

• permutation

• combination

Tags

CCSS.HSS.CP.B.9

Permutation or Combination: Willie and Paul are planning trips to two countries this year. There are 10 countries they would like to visit. One trip will be one week long and the other two weeks.

• permutation

• combination

Tags

CCSS.HSS.CP.B.9