Open In App

GATE | GATE MOCK 2017 | Question 9

Like Article
Like
Save
Share
Report

Four different pens (1, 2, 3, 4) are to be distributed at random in four pen stands marked as 1, 2, 3, 4. What is the probability that none of the pen occupies the place corresponding to its number ?
(A) 17/24
(B) 3/8
(C) 1/2
(D) 5/8


Answer: (B)

Explanation: here total cases will be 4!= 24.
Now cases in favour as per given question –

A    B    C    D (fix pen 2 in A)
2    1    4    3
2    4    1    3
2    3    4    1 - 3 cases

Just like that fixing pen 3 and 4 at A will produce 3 cases each.
Therefore total favourable cases will be 9.

Probability = 9/24 = 3/8


Quiz of this Question


Last Updated : 28 Jun, 2021
Like Article
Save Article
Previous
Next
Share your thoughts in the comments
Similar Reads