Monday

December 22, 2014

December 22, 2014

Posted by **Student** on Sunday, March 4, 2012 at 2:28pm.

A. 0.23

B. 0.34

C. 0.66

D. 0.78

Explanation please??

- Probability -
**MathMate**, Sunday, March 4, 2012 at 4:22pmThe answer is

(n,r)/2^n

Here there are 6 questions, so n=6, and

there are 2^6=64 possible sets of answers.

Since 4 of them are right, the number of combinations with 4 correct out of 6 is

(n,r)=(6,4)=6*5/(1*2)=15

What would be the probability that 4 out of six are correct if the answers are completely random?

**Answer this Question**

**Related Questions**

Probability - Darby guesses the answers to six questions on the math portion of...

Probability - Thank you for the explanation MathMate! Would the answer to this ...

Math - Darby guesses the answers to six questions on the math portion of her ...

Math - Darby guesses the answers to six questions on the math portion of her ...

Statistics - A student is taking a true/false exam with 15 questions. If he ...

math - 11. A Certification Exam containing 20 true and false questions. If a ...

Maths - A true/ false test is given. If a person guesses the answers, the ...

probability - What is the probability of getting 80% or more of the questions ...

math (stats) - A biology professor gives a surprise quiz consist of a true/false...

statistic - Quiz has 6 questions. Each question has five possible answers, only ...