Quiz on Combinations

Which of the following is the formula to find n objects, taken r at a time?

• 25

• 28

• 56

• 64

• 9

• 45

• 72

• 90

How many 3-digit number can be formed from digits 1, 2, 3, 4, 5 ?

(no repetition allowed)

• 16

• 21

• 42

• 60

What is the value ₅C₃?

• 36

• 22

• 19

• 10

The expression ₅₀C₅₀ is equal to _____.

• 0

• 1

• 25

• 50

Which of the following does NOT illustrate combination?

• Enumerating 2 sets of meals out of 5

• Selecting 4 songs from 8 choices for singing audition

• Listing the first 5 players out of 15 for a volleyball match

• Fixing schedule of visitors for 5 days in Lake Leonard

How many different combinations of management can there be to fill the positions of manager, secretary, and advisor of a company knowing that there are 12 eligible candidates?

• 220

• 210

• 120

• 110

Which is the solution that leads to the correct answer in this problem:

"How many different combinations of management can there be to fill the positions of manager, secretary, and advisor of a company knowing that there are 12 eligible candidates"?

The value of CR_(7,2) is ______.

• 15

• 21

• 28

• 34

Answer explanation

this is combination with repetition