16% of 75? pls someone

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?

Aflower has 26 chromosomes. to create a new flower, how many would a sperm cell have what is called?

What is the axis of symmetry of the function f(x)=-(x+ 9)(x-21)