Arithmetic sequence, can anyone help with this questions plz?

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)

To find the inverse of a number a, one can use the equation f(c) = a-1/c=0 where c is the inverse of a use the secant method of finding roots of equations to find the inverse of a = 2.5 ,er = 0.001%

Over the last 4 seconds, a snail has traveled 4/9 of an inch. if the snail traveled the same distance each second, how far did it travel each second?