- #1

- 2,264

- 316

- Homework Statement
- Please see below

- Relevant Equations
- Probability

Arithmetic Sequence

I try to list all the possible sequences:

1 2 3

1 3 5

1 4 7

2 3 4

2 4 6

2 5 8

3 4 5

3 5 7

4 5 6

4 6 8

5 6 7

6 7 8

I get 12 possible outcomes, so the probability is ##\frac{12 \times 3!}{8^3}=\frac{9}{64}##

But the answer key is ##\frac{5}{32}## . Where is my mistake? Thanks