HELP Volume of box

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)

How many square feet of out door carpet will we need for this hole? 8ft 3ft 12ft 4ft

1) prove that 731^3−631^3 is divisible by 100 2) prove that 99^3−74^3 is divisible by 25