Sample space distinction Suppose a pair of dice is thrown 5 times then it's space space will be of the form-(123456,345255.....etc).Can we say that it is equivalent to tossing 1O dice simultaneously?If so ,can you tell me when this condition can happen where we can change the experiment to make it more simplified.

One point in the sample space would be an outcome of all the rolls. That is, a single outcome might look like: $$(1, 5), (2, 3), (2, 2), (5, 2), (3, 6)$$ and the full sample space would be the collection of _all_ such things. You are correct that this is equivalent to just rolling 10 dice; to see this, just drop the parentheses in what I wrote above. I confess that I don't know what you mean when you say "tell me when this condition can happen where we can change the experiment to make it more simplified," though. If you can clarify, I'm happy to comment further.