I have a question regarding operating systems and response time. The book defines response time as:

A)

jobs A, B, C have running times of 10 seconds. A arrives at time 0, B arrives at time 10, C arrives at time 20, what is the average response time with FIFO scheduling? A) 10 seconds B) 20 seconds C) 30 seconds D) 0 seconds

B)

jobs A, and C have running times of 10 seconds. job B takes 25 seconds. A arrives at time 0, B arrives at time 10, C arrives at time 20, what is the average response time with FIFO scheduling with a time slice of 1 second? A) 5 seconds B) 10 seconds C) 20 seconds D) 3.33 seconds

I was hoping someone could walk me through how to solve these problems.

Thanks