If 20% of the girls enrolled in science change their stream to Management, then what will be the new number of Management students altogether?

Answer: Option A

Number of students enrolled in various streams:
$$\begin{array}{rl}& \text{IT → }\frac{20}{100}\times 3500=700\\ & \text{Arts → }\frac{30}{100}\times 3500=1050\\ & \text{Science → }\frac{22}{100}\times 3500=770\\ & \text{Commerce → }\frac{12}{100}\times 3500=420\\ & \text{Management → }\frac{16}{100}\times 3500=560\end{array}$$

Number of girls enrolled in various streams:
$$\begin{array}{rl}& \text{IT → }\frac{18}{100}\times 1500=270\\ & \text{Arts → }\frac{38}{100}\times 1500=570\\ & \text{Science → }\frac{11}{100}\times 1500=165\\ & \text{Commerce → }\frac{21}{100}\times 1500=315\\ & \text{Management → }\frac{12}{100}\times 1500=180\end{array}$$

Number of Management students already enrolled = 560
New required number
$$\begin{array}{rl}& =560+\left(\frac{20}{100}\times 165\right)\\ & =560+33\\ & =593\end{array}$$