2、(365- 13)/4=88

3、(8-4.5)×2=7

4. Every time boys and girls move * * *: 1800/4=450 yuan. Assuming all boys, then 65 boys have to move 65×8=520 pieces at a time, with a difference of 520-450=70 pieces. Every girl is treated as a boy, and the result will be 2 more than the actual one. Now a * * * is 70 yuan more, so girls have 70/2=35 and boys have 65-35=30.