Astudent is taking an exam consisting of three questions selected randomly from a list of 100 questions. to pass, he needs to answer all three questions. what is the probability that the student will pass the examination if he knows the answers to 90 questions on the list?

The probability that the student will pass is 72.6%

Step-by-step explanation:

There are 100 questions total.

The order that the questions are selected makes no diffence. For example, if  Q3, Q28, Q57 are selected in this order or as Q28, Q57, Q3, it is the same exam. So it is a combination problem.

Combination Formula:

A combination of n elements from a set of m objects has the following formula:

Probability:

The probability is the number of desired outcomes divided by number of total outcomes.

The number of total outcomes is the combination of 3 questions from a set of 100 questions. So, we have n = 3, m = 100.

There are 161700 total outcomes.

The number of desired outcomes is the combination of 3 questions from a set of 90 questions(the questions that the student knows the answers). So, we have n = 3, m = 90.

Probability P = D/T = 117480/161700 = 0.726 = 72.6%

The probability that the student will pass is 72.6%

the clues that signal the reader should change tone are the punctuation marks, the grammatical signs. for example, the quotation marks at the beginning of something someone else said literally or the exclamation marks.

the tone of the first line of dialogue until "gettysburg" is a kind tone, a tone of advise. the narrator is trying to the other person in doing something he or she obviously is finding hard to do by giving a piece of advise and bringing up a memory of a successful similar case.

the clue that the reader understand how to read the word "bang" is the exclamation mark. it gives the word a surprise tone, a strong accent.

the best tone for reading the word "bang" is an exciting tone, a surprise one, even a loud one.

the words that should be read with a formal tone are the ones that give factual information. the sentence: mister lincoln couldn't think of anything to say at the gettysburg" gives information about an event and it needs to be read formally, also, when the narrator wants to transmit calmness, a formal and slow tone is needed, because people also transmit messages with the vibrations of our voices and tones.