There is the probability that a mathematics teacher will give an unannounced test during any class meeting is 1/ 5. If a student is absent twice, what is the probability that he will miss at least one test?
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There are two ways to solve this problem:
Understanding :
1) Probability that
student will miss at least one test = Probability that student will miss 1 test out of 2 + he will miss both.
2) Probability he will miss at least one test =
1- P(He will not miss both test)
----------------------------------------
Here, "P "denotes Probability
and Order is important.
Steps :
1) P( Miss first test) = 1/5 * 4/5 = 4/25
2) P (Miss second test) = 4/5 * 1/5 = 4/25
3) P(Miss both) = 4/5 *4/5 = 16/25 .
After, this see pic attached to it.
Here , I will show you both methods.
For calculation see Pic :
Understanding :
1) Probability that
student will miss at least one test = Probability that student will miss 1 test out of 2 + he will miss both.
2) Probability he will miss at least one test =
1- P(He will not miss both test)
----------------------------------------
Here, "P "denotes Probability
and Order is important.
Steps :
1) P( Miss first test) = 1/5 * 4/5 = 4/25
2) P (Miss second test) = 4/5 * 1/5 = 4/25
3) P(Miss both) = 4/5 *4/5 = 16/25 .
After, this see pic attached to it.
Here , I will show you both methods.
For calculation see Pic :
Attachments:
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