Find an explicit formula for h(n)

Help!

Ijust need to see how to do this. so you don’t have to answer all of them just a step by step explanation of one.

Neoli is a nurse who works each day from 8: 00 am to 4: 00 pm at the blood collection centre. she takes 45 minutes for her lunch break. on average, it takes neoli 15 minutes to collect each sample and record the patient's details. on average, how many patients can neoli see each day?

F(x) = 1/x g(x)=x-4 can you evaluate (g*f)(0) ? why or why not?