Solution (By Examveda Team)

Number of lecturers in various subjects are:
$$\eqalign{ & \text{Chemistry → } \frac{13}{100}\times1600 = 208 \cr & \text{Education → } \frac{18}{100}\times1600 = 288 \cr & \text{Hindi → } \frac{12}{100}\times1600 = 192 \cr & \text{Mathematics → } \frac{21}{100}\times1600 = 336 \cr & \text{Physics → } \frac{14}{100}\times1600 = 224 \cr & \text{Zoology → } \frac{22}{100}\times1600 = 352 \cr} $$

Subject	Number of Males	Number of Females
Chemistry	208 × $$\frac{1}{8}$$ = 26	208 - 26 = 182
Education	288 × $$\frac{5}{8}$$ = 180	288 - 180 = 108
Hindi	192 × $$\frac{1}{4}$$ = 48	192 - 48 = 144
Mathematics	336 × $$\frac{3}{7}$$ = 144	336 - 144 = 192
Physics	224 × $$\frac{9}{14}$$ = 144	224 - 144 = 80
Zoology	352 × $$\frac{7}{16}$$ = 154	352 - 154 = 198

$$\eqalign{ & \text{Required %} \cr & = \left(\frac{192}{192+182}\times100\right)\% \cr & = \left(\frac{192}{374}\times100\right)\% \cr & = \frac{9600}{187}\% \cr & = 51.3\% \cr & \approx 51\% \cr} $$