Can somebody help me

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)

If f(x)=3x+1 and f^-1=x-1/3, then f^-1(7)=

Evaluate the discriminant of each equation. tell how many solutions each equation has and whether the solutions are real or imaginary. 4x^2 + 20x + 25 = 0