﻿ If the papers of 4 students can be checked by any one of the 7 teachers, then the probability that all the 4 papers are checked by exactly 2 teachers is : Kaysons Education

# If The Papers Of 4 Students Can Be Checked By Any One Of The 7 Teachers, Then The Probability That All The 4 Papers Are Checked By Exactly 2 Teachers Is

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## Question

### Solution

Correct option is

6/49

The total number of ways in which papers of 4 students can checked by seven teachers is 74.

The number of ways of choosing two teachers out of 7 is  the number of ways in which they can check four papers is 24. But this includes two ways in which all the papers will be checked by a single teacher. Therefore, the number of ways in which 4 papers can be checked by exactly two teachers is 24 – 2 = 14.

∴ the number of favorable ways

Thus,   the required probability =

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