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3 votes
A die is rolled 108 times. How many times can you expect to roll a 2?

A. 54
B. 24
C. 18
D. 36

User Leftbit
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2 Answers

3 votes
The probability of rolling a specific number on a die is 1/6. Therefore the expected number of times a 2 is rolled in 108 rolls of the die is:

(108)/(6)=18
User Spaceemotion
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5 votes
The die can land in 6 different ways.
Only one of them is a 2.
So the probability of rolling a 2 on any roll is 1/6 .
In a large number of rolls, you expect roughly 1/6 of them to be a 2.

In 108 rolls, you should expect a 2 somewhere around

(108/6) = 18 times.
User Mark Schuurman
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7.8k points