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?

A wholesaler bought walnuts and peanuts, the price of walnut per kg being thrice that of peanut per kg . He then sold $8 \mathrm{~kg}$ of peanuts at a profit of $10 \%$ and $16 \mathrm{~kg}$ of walnuts at a profit of $20 \%$ to a shopkeeper. However, the shopkeeper lost $5 \mathrm{~kg}$ of walnuts and $3 \mathrm{~kg}$ of peanuts in transit. He then mixed the remaining nuts and sold the mixture at Rs. $166$ per kg, thus making an overall profit of $25 \%$. At what price, in Rs. per kg, did the wholesaler buy the walnuts?

If a seller gives a discount of $15 \%$ on retail price, she still makes a profit of $2 \%$. Which of the following ensures that she makes a profit of $20\%$?