Problem 3. In a school, 35% are girls, and there are 252 more boys than girls. How many boys and how many girls are there in the school?
Solution. In the school, there are $65\%$ boys, which means there are $30\%$ more boys than girls. If $30\%$ is 252 children, then $10\%$ is 84 children. Therefore, we conclude that there are 840 students in the school, of which 294 are female, and 546 are male.