Asingle die is rolled. find the probability of rolling a 2 or an odd number

The candy store is having a 30% off sale. emma is going to buy $7.50 worth of candy.how much will she pay after the discount

Can someone show me step by step how to do this?

Acertain drug is made from only two ingredients: compound a and compound b. there are 3 millimeters of compound a used for every 4 millimeters of compound b. if a chemist wants to make 693 milliliters of the drug, how many milliliters of compound a are needed?