What is a volume, and how is it measured?

The expression 1.01*1.005(^t) gives the amount of money, in thousands of dollars, in carter's savings account (t) years after he opens it. what does 1.01 represent in this expression?

1. if events a and b are non-overlapping events, how do you find the probability that one or the other occurs? 2. what does it mean if p(a or b) equals 1?

700 miles the train takes 5 hours to a travel the distance at what unit rate is the train traveling?