*I will mark you 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?

Asystem of equations has 1 solution.if 4x-y=5 is one of the equations , which could be the other equation ?

Adam used 1072.4 gallons of water over the course of 7 days. how much water did adam use, on average, each day?