There are 15 boys and 10 girls in Miss Li's class. She wants to group all the students so that each group has the same number of boys and the same number of girls. What is the greatest number of groups she can have?
A pet shop manager wants the same number of birds in each cage. He wants to use as few cages as possible, but can only have one type of bird in each cage. If he has 42 parakeets and 18 canaries, how many birds will he put in each cage?
There are 111 guests attending a party. There are 15 servers. Each server has the same number of guests to serve. Jess will serve any extra guests. How many guests will Jess be serving?