I'm assuming your trying to find how much pizza he has left.
You need to subtract the two fractions because the denominators are already the same.
When subtracting fractions, you leave the denominator and regularly subtract the numerator.
Your answer will be 2/8 which equals 1/4th
Using the binomial distribution, it is found that:
The probability that the student will get 15 correct questions in this test by guessing is 0.0207 = 2.07%.
For each question, there are only two possible outcomes, either the guess is correct, or it is not. The guess on a question is independent of any other question, hence, the binomial distribution is used to solve this question.
Binomial probability distribution
The parameters are:
- x is the number of successes.
- n is the number of trials.
- p is the probability of a success on a single trial.
In this problem:
- There are 20 questions, hence
.
- Each question has 2 options, one of which is correct, hence

The probability is:

In which:







Then:

The probability that the student will get 15 correct questions in this test by guessing is 0.0207 = 2.07%.
You can learn more about the binomial distribution at brainly.com/question/24863377
Answer:
OPtion B)
Step-by-step explanation: