5 (m - 3) = 40 What do 5m and m represent?

(Quick Question I NEED REAL QUICK!)
(Thanks)

Airline passengers arrive randomly and independently at the passenger-screening facility at a major international airport. the mean arrival rate is 10 passengers per minutes. compute the following probabilities. p(x = 4) p(x > 11)

What is the definition of exponential decay?

The figures below are made out of circles, semicircles, quarter circles, and a square. find the area and the perimeter of each figure and give your answers as a completely simplified exact value in terms of π (no approximations).