Please help asap, will mark brainliest :))

Does the problem involve permutations or? combinations? do not solve. the matching section of an exam has 4 questions and 7 possible answers. in how many different ways can a student answer the 4 ? questions, if none of the answer choices can be? repeated?

Express the following as a function of a single angle. cos(60) cos(-20) - sin(60) sin(-20)

How long must $542 be invested at a rate of 7% to earn $303.52 in interest? in a easier way