Jen brought some sesame bagels and some plain bagels .The ratio of the number of sesame bagels to the number of plain bagels is 1:3 what fraction of bagles are plain?,what percent of the bagels are pl

Jen brought some sesame bagels and some plain bagels .The ratio of the number of sesame bagels to the number of plain bagels is 1:3 what fraction of bagles are plain?,what percent of the bagels are plain,if Jill bought 2dozen bagels,how many of each type of bagel did she buy?

Pls give the explanation how did you get the answer of these three questions!!