Question

The probability that a teacher will given a unannounced test is $\frac{1}{4}$. If a student was absent twice, then probability that he will missed at least one test is

• A. $\frac{1}{2}$
• B. $\frac{7}{16}$
• C. $\frac{1}{4}$
• D. $\frac{3}{4}$

Answer 1

The correct option is B $\frac{7}{16}$

the probability that student missed at least one test
= $1$ - probability that no test was taken on those two days
= $1$ - $\frac{3}{4}\times \frac{3}{4}$ $=7/16$