When rounding to the nearest hundred, what is the least whole number that rounds to 900?

Ineed how factor it by finding the gcf

Beth makes batches of bluberry muffins and banna muffins. each batchis 6 muffins. she makes 2.5 batches of bluberry muffins. how many batches of bananna muffins should beth make if she wants to have a total of 60 muffins?

Guys i really need or i have to stay late up night