If the sales tax reduced from \( 3 \frac{1}{2} \% \) to \( 3 \frac{1}{3} \% \), then what difference does it make to a person who purchases an article with market price of Rs. 9000?
In a survey, 60 % of 200 students prefer online classes, and 25 % of the remaining prefer hybrid classes. How many students prefer neither?