The revenue R in dollars received from selling radios is () = (90 − ). a) Evaluate (20) and interpret the result. b) What number of radios sold maximize revenue? c) What number of radios should be sold for revenue to be $2000 or more?

Ireally need ! if a musician uses his credit card to pay for a new violin that costs $2,900 and does not pay on it until the second month, what will the 3.35% monthly interest charge be at the end of the first month? show your work or explain how you got your answer.