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:
Answer & explanation
Correct answer: option 2
P (teacher misses at least 1 test)
= 1 - P (misses no test) = 1 – P (both days test was not given) = $1-\frac{4}{5}×\frac{4}{5}=\frac{9}{25}$