I have a problem....

A bus arives to station 07.15 but is often late. Uniform distribution!

Bus is late between 0 and 7 minutes!

a

a) What is probability that buss arrives 07.18?

b) What is probability that buss arrives between 07.17 and 07.18?

should i begin with 0<3<=7(minutes) and 0<2<7 ???

Thanks