. There are 6 items in column A and 6 items in column B. A student is asked to match each item in column A with an item in column B. How many possible, correct or incorrect, answers are there to this question?
Given: The number of items in column A = 6 and in column B = 6
A student is asked to match each item in column A with an item in column B
To find: Possible number of correct or incorrect answers which he can give
Let the items of column A are fixed i.e. they arrangement is not changing
Now, we just have to arrange items of column B
Formula used:
Number of arrangements of n things taken all at a time = P(n, n)
∴ The total number of ways in which this can be done
= the number of arrangements of 6 things taken all at a time
= P(6, 6)
{∵ 0! = 1}
= 6 × 5 × 4 × 3 × 2 × 1
= 720
Hence, possible number of correct or incorrect answers which a student can give are 720