7.2. On his birthday, Nikita decided to treat his classmates and took 4 bags of candies to school, each containing the same number of candies. He gave out 20 candies to his classmates, which was more than $60 \%$ but less than $70 \%$ of all the candies he had. How many candies did Nikita have in total?
Answer: 32.

Solution. Suppose there were $x$ candies in each bag.

Then $\frac{6}{10}<\frac{20}{4 x}<\frac{7}{10}$. Therefore, $\frac{50}{7}<x<\frac{50}{6}$, i.e., $7<x \leq 8, x=8$. Total candies - 32.