In a standard deck of cards, what is the probability of drawing a black card followed by drawing a heart?

Factor completely. 4p^2 + 36p + 81 express the answer in the form (ap + b)^2

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

The random variable x represents the number of phone calls an author receives in a day, and it has a poisson distribution with a mean of 8.7 calls. what are the possible values of x