Find tan a. can someone me with this one? ?

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?

Ajar of gumballs contains 4 reds, 2 greens, and 6 blues. what is the probability of getting two blues in a row without replacement?

How to do this , and can some one explain