Problem 5.4. At the end-of-the-year school dance, there were twice as many boys as girls. Masha counted that there were 8 fewer girls, besides herself, than boys. How many boys came to the dance?
Answer: 14.

Solution. Let there be $d$ girls at the disco, then there are twice as many boys, i.e., $d+d$. The number of girls, excluding Masha, is $d-1$ (all except herself).

Since there are 8 more boys than the other girls, excluding Masha, then $d+d=(d-1)+8$. From this, it follows that $d=7$, so the total number of boys is $7+7=14$.