Spearman's Rank Coefficient for Repeating Ranks

Q.

In a $\mathrm{B}$ School, there are $15$ teachers who teach marketing or finance. Of these, $8$ teach finance and $4$ teach both marketing and finance. How many teach marketing but not finance?

1. $15$

2. $20$

3. $11$

4. None of these.

Q.

If Pam works more than $40$ hours per week, her hourly wage for every hour over $40$ is $1.5$ times her normal hourly wage of $\$7$.

Write a piecewise-defined function that gives Pams weekly pay $P\left(h\right)$ in terms of the number of hours $h$ that she works.