4(x+y)+8(x+y) distribute and simplify

The random variable x is the number of occurrences of an event over an interval of ten minutes. it can be assumed that the probability of an occurrence is the same in any two-time periods of an equal length. it is known that the mean number of occurrences in ten minutes is 5.3. the appropriate probability distribution for the random variable

A. 127 cm^2 b. 144.5 cm^2 c. 172 cm^2 d. 50 cm^2

An arc subtends a central angle measuring 7pi/4 radians what fraction of the circumference is this arc?