Determine the number of elements in the sample space for each of the following:

1. tossing a coin three times

2. the order that the top 5 students will receive their diplomas.

3. tossing a pair of dice.

Sample space is the set of possible outcomes of an experiment.
1. Tossing a coin three times
There are possible outcomes.
Tossing the coin for the first time it can be a haid  (H) or a tail (T). So, we can have this outcomes:
HHH
HHT
HTH
THH
TTH
THT
TTT
total: 6 outcomes
2. The order that the top 5 students will receive their diplomas.
Here we need to find the number of permutations:  5!=5*4*3*2*1=120
3. Tossing a pair of dice
The possible outcomes are the following: (a,b), where a is the first dice and b is the second dice
(1,1)(1,2)(1,3)(1,4)(1,5)(1,6)(2,1)(2,2)(2,3)(2,4)(2,5)(2,6)(3,1)(3,2)(3,3)(3,4)(3,5)(3,6)(4,1)(4,2)(4,3)(4,4)(4,5)(4,6)(5,1)(5,2)(5,3)(5,4)(5,5)(5,6)(6,1)(6,2)(6,3)(6,4)(6,5)(6,6) , total 36 possible outcomes.

No because if you do the higher number minus the lower number you will get a positive. if you do it the other way around you will get a negative number