Level 3
Alex invited 9 friends to his party. He gave each of his friends 5 sticks of barbecued chicken. In the end, Alex had 2 sticks of barbecued chicken left. How many sticks of barbecued chicken did he have at first?
Level 2
A library has a certain number of books. In January, the library bought 325 new books and 280 books were loaned out. In February, the library lost 350 books and loaned out 210 books, after which 2831 books were left. How many books were there in the library in the beginning of January?
Level 3
Andy has 3 toy boats. Melvin has 2 more toy boats than Andy. Farid has 3 fewer toy boats than Melvin. How many toy boats do they have altogether?