Question

HELP WITH Probability


There are 5 questions on a multiple choice exam, each with five possible answers. If a student guesses on all five questions, what is the probability the student gets one question correct? Express your answer as a percent rounded to the nearest tenth.











41.0%










25.1%










20.5%










28.7%

Answer 1

@iGreen

Answer 2

k

Answer 3

@FibonacciChick666

Answer 4

what's the chance for the first one?

Answer 5

.2 I think,

Answer 6

use a fraction, life is easier

Answer 7

try this
https://answers.yahoo.com/question/index;_ylt=A0LEVytgkIlUlIEA5AFXNyoA;_ylu=X3oDMTEzZzhicGdqBHNlYwNzcgRwb3MDMQRjb2xvA2JmMQR2dGlkA1ZJUDUxMl8x?qid=20090612151159AACPKUD

Answer 8

ok, then how about the second one? Whats the chance of getting it right?

Answer 9

the chance of getting it right is 0.2, getting it wrong is 0.8

Answer 10

@FibonacciChick666

Answer 11

ok, so are they all a 1 in 5 chance?

Answer 12

by themselves that is

Answer 13

"the chance of getting it right is 0.2, getting it wrong is 0.8"
That is correct for answering one question.
This is the probability of success (p=0.2) in a Bernoulli trial (either right or wrong, no other results).
When there are n trials with the same probability of success, and each trial is independent of each other, you could use the binomial distribution, which gives the probability of r successes in n trials:

\(P(r)=\frac{n!}{n-r!\ r!}p^r(1-p)^{n-r}\)

Take out your calculator and find the answer. Here n=5, p=0.2, r=1.

Answer 14

41% @mathmate

Answer 15

That is correct! Good job! :)