Is rolling doubles a simple event or compound event? explain.

You have to consider the sample space. In this example the sample space 
is {1,2,3,4,5,6}
A simple event can be defined as a SINGLE outcome : Example getting a 3 OR 5 OR any other number from the sample space.
Now if you roll 1 dice & you want to get an even number (2,4,6) then you have chosen from the sample space 3 outcome & this is a compound event
Equally if you roll 2 dice and want to get "one" and/or "three" this is a compound event since you have chosen 2 outcome from the sample space.
Mind you, if you want 5 And 5 when rolling two dice it's a simple event because you have chosen ONE outcome from the sample space.
Hope this will help you to understand this kind of problem

You have to consider the sample space. In this example the sample space

is {1,2,3,4,5,6}

A simple event can be defined as a SINGLE outcome: Example getting a 3 OR 5 OR any other number from the sample space.

Now if you roll one dice & you want to get an even number (2,4,6), then you have chosen from the sample space three outcomes & this is a compound event

Equally, if you roll two dice and want to get "one" and "three," this is a compound event since you have chosen two outcomes from the sample space.

Mind you, if you want 5 And 5 when rolling two dice it's a simple event because you have chosen ONE outcome from the sample space.

The mean is equal to the median according to e2020