An automotive manufacturer recommends servicing brake systems as well as replacing worn parts every 20000 miles. The reliability of single-wheel braking system has been found through accelerated life testing to be 0.8855 at the 20000 miles.
A) If at least one front brake and one rear brake should function for 4-wheel vehicle to safely stop. Determine the system reliability at 20000 miles.
B) What is the system reliability at 20000 miles if at least any two brakes must function?