Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Probability

Question:

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

Options:

7/25

9/25

16/25

24/25

Correct Answer:

9/25

Explanation:

P (teacher misses at least 1 test)

= 1 - P (misses no test) = 1 – P (both days test was not given) = $1-\frac{4}{5}×\frac{4}{5}=\frac{9}{25}$