CAT (QA) PYQs

Mayank buys some candies for Rs $15$ a dozen and an equal number of different candies for Rs $12$ a dozen. He sells all for Rs $16.50$ a dozen and makes a profit of Rs $150$. How many dozens of candies did he buy altogether?

The manufacturer of a table sells it to a wholesale dealer at a profit of $10 \%$. The wholesale dealer sells the table to a retailer at a profit of $30\%$. Finally, the retailer sells it to a customer at a profit of $50\%$. If the customer pays Rs $4290$ for the table, then its manufacturing cost (in Rs) is

One part of a hostel's monthly expenses is fixed, and the other part is proportional to the number of its boarders. The hostel collects $1600$ per month from each boarder. When the number of boarders is $50$, the profit of the hostel is $200$ per boarder, and when the number of boarders is $75$, the profit of the hostel is $250$ per boarder. When the number of boarders is $80$, the total profit of the hostel, in INR, will be