Question

Nicks scool is closed ln saturday and sunday if his maths tacher wants to take a test in the month of august 2019.where only thursday, friday saturday xomes five tines what is the probabilty that the test will fall on any Monday

Answer 1

$$\def\arraystretch{1.5} \begin{array}{c:c:c:c:c:c:c} Sun. & Mon. & Tues. & Wed. & Thurs. & Fri. & Sat. \\ \hline & & & & 1 & 2 & 3 \\ \hdashline 4 & 5 & 6 & 7 & 8 & 9 & 10 \\ \hline 11 & 12 & 13 & 14 & 15 & 16 & 17 \\ \hline 18 & 19 & 20 & 21 & 22 & 23 & 24 \\ \hline 25 & 26 & 27 & 28 & 29 & 30 & 31 \\ \hline \end{array}$$

In August Monday comes four times

$$P(test \ will\ fall \ on\ Monday)={4 \over 31-9}={2 \over 11}\approx0.1818$$