$11$ papers are set for an examination in which two are of mathematics. Number of ways in which papers can be arranged so that mathematics papers do not come together?
There are $11!$ ways in total. If we treat two mathematics papers as one unit then there will be $10!$ ways in which they will be always together.
Therefore, the answer should be $11!-10!$, but the answer is wrong. Please help.
Best Answer
HINT:
The order of the $2$ mathematics papers is significant.
Multiply $10!$ by the number of ways in which you can arrange those items.