HELP quick algebra 1 problems!! THANK YOUUU?

ahhhh, my grade is slipping big time, i cant afford to get these wrong, please help! even just answer one of these, i dont care, i just need the work and answer!!! then i can study it later, but pleaseeee help! *** YOU DONT HAVE TO ANSWER THEM ALL :) 1.Renata paid $21.25 for a sweater that was marked down from 25$. what % of the original price was the sale price? 2.Jerry started a retail establishment. he marked up items 30 % of his wholesale cost (jerry's purchase price). if he sold an item for $715, what did jerry pay for it? 3. Twice a # is decreased by 9, and this sum is multiplied by 4. the result is 8 less than 10 times the #. what is the #? write an equation; solve and answer the question.