Please actually answer me

Rockwell hardness of pins of a certain type is known to have a mean value of 50 and a standard deviation of 1.1. (round your answers to four decimal places.) (a) if the distribution is normal, what is the probability that the sample mean hardness for a random sample of 8 pins is at least 51?

Solve: 3x+y=6 4x-2y=18 show all work !

He that is measured at 220° is a reflex angle. the opposite angle is obtuse. find the measure of obtuse .