Homework SourseA hat contains five slips of paper numbered 1234and 5 Two ar
A hat contains five slips of paper, numbered 1,2,3,4,and 5. Two are chosen at random, without replacement, and X is the sum of the two numbers. Write down the possible values of X and their probabilities; from them find EX.
Solution
Consider the possible results:
Taking the average of the last column,
EX = 6 [ANSWER]
| First Result | Second Result | Sum |
| 1 | 2 | 3 |
| 1 | 3 | 4 |
| 1 | 4 | 5 |
| 1 | 5 | 6 |
| 2 | 1 | 3 |
| 2 | 3 | 5 |
| 2 | 4 | 6 |
| 2 | 5 | 7 |
| 3 | 1 | 4 |
| 3 | 2 | 5 |
| 3 | 4 | 7 |
| 3 | 5 | 8 |
| 4 | 1 | 5 |
| 4 | 2 | 6 |
| 4 | 3 | 7 |
| 4 | 5 | 9 |
| 5 | 1 | 6 |
| 5 | 2 | 7 |
| 5 | 3 | 8 |
| 5 | 4 | 9 |
