Help please I don’t understand

Given the choice between receiving $1.000.000 in one month or a single penny-doubled everyday for the period of one month; which option would you choice? show your work to support your answer. (assume that 1 month=30 days)

For one history test, keith had to answer 40 questions. of these 40 questions, keith answered 28 of them correctly. what percent did keith get on his history test? round your answer to the nearest tenth if necessary

You are a clerk at convenience store. a customer owes 11.69 for a bag of potatoes chips. she gives you a five dollar bill. how much change should the customer receive?