The fire department recently conducted a study on the amount of time it takes fire crews to get on the road once the alarm has sounded. After conducting their study, they found that the average time to get on the road was 150 seconds; the standard deviation was 20 seconds. Assume the total time has a normal distribution.

a) [2 marks] For a randomly chosen fire alarm, what is the probability that the time it takes fires crews to get on the road exceeds 180 seconds?

b) [2 marks] Ninety five percent of fire alarms take crew less than how many seconds to get on the road?

c) [2 marks] It took the fire crew 105 seconds to get on the road for the last fire alarm. Is this an unusual amount of time? Justify your answer.