Question

Suppose that 3 ​thank-you notes are written and 3 envelopes are addressed.​ Accidentally, the notes are randomly inserted into the envelopes and mailed without checking the addresses. What is the probability that all the notes will be inserted into the correct​ envelopes? The probability is 0.166667.

Answer 1

The probability that all the notes will be inserted into the correct envelopes is 1/6 or 0.166667.

Explanation:

All the possible combinations are given by 3!=3x2x1=6. There are 6 possible ways in which the letters can be mailed. One of these ways is that the direction is correct. So the probability is 1/6=0.166667.