Explanation
We are required to create a word problem that can be represented by this mathematical statement and solve the problem.

This is achieved thus:
Question:
In how many ways can you arrange 12 textbooks in a row if 3 are identical Maths textbooks and 9 are identical Physics textbook.
Solution:
The total textbooks = 12
Identical textbooks are Maths(3) and Physics(12)
Therefore, we have:

Hence, the answer is:
