P$5.$ Review the car$-$caravan analogy in Section $1\mathrm{.}4.$ Assume a propagation speed of $100k\frac{m}{?}$ hour.

a$.$ Suppose the caravan travels $150km,$ beginning in front of one tollbooth, passing through a second tollbooth, and finishing just after a third tollbooth. What is the end$-$to$-$end delay?

b$.$ Repeat $($a$),$ now assuming that there are eight cars in the caravan instead of ten.