Help pls

Little’s law firm has just one lawyer. customers arrive randomly at an average rate of 6 per 8 hour workday. service times have a mean of 50 minutes and a standard deviation of 20 minutes. how long does a customer spend at little’s law firm on average?

Prove that the value of the expression 7^8–7^7+7^6 is divisible by 43.

Graph the equationy=x^2 -[tex]y = x^{2} - 2[/tex]