Answer:
4845 combinations
Step-by-step explanation:
Whenever there is a selection of some elements from a certain group, there are several ways to do so. There are different combinations from the group which can be selected. The concept of combination means that there are certain number of elements to be selected from the group and there is no importance given to the order of the selection. The total number of students are 20, and 4 out of them have to be selected. It can be clearly seen that the order of selection does not matter, therefore the formula to be used is:
Combinations = 20C4 = (20*19*18*17)/(4*3*2*1) = 4845.
So the correct answer is 4845 combinations!!!
The disstance between -125 and 78 is 47
The empirical probability of a 4 or 5 is
(count of outcome = 4 or 5)/(count of all outcomes) = (44 +40)/240 = 7/20
The problem statement asks you to assume the outcomes will remain in this proportion going forward. That is, the number of outcomes (n) of 4 or 5 in the next 60 rolls of the number cube is expected to satisfy
7/20 = n/60
Multiplying that by 60 gives
n = 60*(7/20) = 21
Selection D is appropriate.
