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The probability that a teacher will give...

The probability that a teacher will give an unannounced test during any class meeting is 1/5. If a student is absent twice, find the probability that the student will miss at least one test.

A

`4/5`

B

`2/5`

C

`7/25`

D

`9/25`

Text Solution

Verified by Experts

The correct Answer is:
D
Probability that one test is held `=2xx1/5xx4/5=8/25`
Probability that tese in held on both days `1/5xx1/5=1/25`
`therefore` Probability that the student misses at least one test
`=8/25+1/25=9/25`
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