The number of boys to girls in math class is 2:3 If there are 21 girls in Mrs. Vest's math class, how many boys are there? Can we use what we know about quivalent ratios to figure out how many boys are in the class?​

Achild has a box full of colored building blocks. she will choose one block without looking. the odds against choosing a blue block are 4/7. what is the probability of choosing a blue block? amanda is playing a role-playing game with her friends. she will roll dice to determine if her character unlocks a treasure chest. the probability of her character unlocking the treasure chest is 13/20. find the odds in favor of her character unlocking the treasure chest.