Pick the right count fast

Exercise and reference answers

Questions

1. Question

   0! equals

   Choices

   1. 1
   2. 0
   3. undefined

   Correct choice

   1

2. Question

   5! equals

   Choices

   1. 25
   2. 120
   3. 720

   Correct choice

   120

3. Question

   Subsets of a set of 5 objects

   Choices

   1. 10
   2. 25
   3. 32

   Correct choice

   32

4. Question

   C(n, r) also equals

   Choices

   1. C(n, n - r)
   2. C(r, n)
   3. P(n, r)

   Correct choice

   C(n, n - r)

5. Question

   Ways for 9 swimmers to line up

   Choices

   1. 504
   2. 362,880
   3. 3,024

   Correct choice

   362,880

6. Question

   Rearrangements of DISTINCT

   Choices

   1. 5,040
   2. 40,320
   3. 10,080

   Correct choice

   10,080

Instructions

Tap the correct answer for each prompt.

Explanation