posted by kali .
You have a bag with 60 black jelly beans and 240 red ones.
a) If you draw one jelly bean out of the bag, find the probability that it is black.
b) If you add 60 black jelly beans to the original bag and draw out a bean, what is the probability that it is black?
c) How many black beans do you need to add to the original bag to double the original probability of drawing a black bean?
d) Write an equation that represents the problem in part (c).
I GOT A AND B JUST NEED C AND D PLEASE?(: