Question and answers in probability

Topic:- Probability

Probability, or chance, is a way of expressing knowledge or belief that an event will occur or has occurred. In mathematics the concept has been given an exact meaning in probability theory, that is used extensivelstatisticy in such areas of study as mathematics, s, finance, science, and philosophy to draw conclusions about the likelihood of potential events and the underlying mechanics of complex systems.

This math help have some question and answers in probability

Question1- A student had to be chosen from Ann’s class. There were 11 boys and 11 girls in total
in her class. The teacher wrote their names on separate pieces of paper, and then took
out one of the papers without looking. What is probability of selecting a boy?

Ans:-The probability of selecting a boy 11/22, so P = 0.5.

Question2-Thomas had a bag with 30 marbles: 12 blue, 7 red, 5 white and the rest were gray.

a) He took a marble. What is the probability that it is a blue marble?

b) If he puts the marble back and takes another one, what is the probability of
taking a red one?

c) Thomas took a grey marble and didn’t put it back. What is the probability of
taking another grey marble immediately after that?
Answers:-

a)
The probability of taking a blue one is 12/30, so P = 0.4

b)
The probability of taking a red one is 7/30, so P = 0.23.
c)
The probability of taking a gray one is 5/29, so P = 0.17.


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