Answer:
The probability that the student answers at least seventeen questions correctly is
.
Step-by-step explanation:
Let the random variable <em>X</em> represent the number of correctly answered questions.
It is provided all the questions have five options with only one correct option.
Then the probability of selecting the correct option is,

There are <em>n</em> = 20 question in the exam.
It is also provided that a student taking the examination answers each of the questions with an independent random guess.
Then the random variable can be modeled by the Binomial distribution with parameters <em>n</em> = 20 and <em>p</em> = 0.20.
The probability mass function of <em>X</em> is:

Compute the probability that the student answers at least seventeen questions correctly as follows:


Thus, the probability that the student answers at least seventeen questions correctly is
.
15/3 + 4/3 = 19/3
All you have to do is subtract 4/3 from 19/3 to get 15/3
Okay so there are 52 weeks in a year and she runs 12 miles every week so multiply 52 times 12 which equals 624
X= 5
Set them equal to each other
2x-2=x+3
Subtract x to the other side
X-2=3
Add two to the other side
X=5
Hope it helps
2/3x=(-20)
X=(-20)x 3/2 ( 2/3 actually changes into 3/2(it's reciprocative form)when the number crosses the equal sign)
X=(-10) x 3
X= (-30)
Hope it helps....