math
posted by becky on .
The weights of adult longtongued fruit bats are known to be normally distributed with a mean of 20.22 grams and a standard deviation of 3.23 grams. What is the probability that a randomly selected bat will:
a) weigh at most 15 grams?
b) weigh less than 30 grams?

Suppose that you select 2 cards without replacement from an ordinary deck of playing cards.
a) If the first card that you select is a heart, what is the probability that the second card that you select is
an heart?
b) If the first card that you select is an ace, what is the probability that the second card that you
select is a spade?