Three letters are to be sent to different persons and addresses on three envelopes are also written.

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14.Probability

easy

Three letters are to be sent to different persons and addresses on the three envelopes are also written. Without looking at the addresses, the probability that the letters go into the right envelope is equal to

A

$\frac{1}{{27}}$

B

$\frac{1}{9}$

C

$\frac{4}{{27}}$

D

$\frac{1}{6}$

Solution

(d) Total no. of ways placing $3$ letters in three envelops $ = 3\,!,$

out of these ways only one way is correct.

Hence the required probability $ = \frac{1}{{3\,!}} = \frac{1}{6}.$

Standard 11

Mathematics

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