Ans: (a) $43$ (b) $20\%$
- The number of female interviewees
$\begin{array}{cl}
= & 172 \times (1-75\%) \\
= & 43
\end{array}$ - The percentage of female interviewees
$\begin{array}{cl}
= & \dfrac{43}{172 + 43} \times 100\% \\
= & 20\%
\end{array}$
