X can not = 0 because if I did your answer would not be a fraction it would be 0
7 1/10 is the answer bc you have the plain 7 and .1 is 1/10
30 divided by 3. Their are 3 sets of ten by 30 positives
Probaility in general is defined as the ratio of positive outcomes over the total number of outcomes.
In the first example, the total outcomes are 16; let us count the positive ones. There are 8 even numbers from 1-16. The prime numbers are 2,3,5,7,11,13. Out of those, only 5 are odd. Hence, in total there are 13 positive outcomes. Thus, the probability is 13/16=81.25%
Let's restrict the problem to the students that studied for the exam; the proportion is 0.57 of the total students. 0.52 of the total students studied and saw an increase in their exam. Hence, the probability that a student who studied saw an increse is 0.52/0.57 (here a positive outcome is the proportion that saw an increase and the total outcomes are all the students that studied). 0.52/0.57=91.22%