There are 52 white keys and 36 black keys on a standard piano. what is the probability that if a person did not look and hit the keyboard twice that he or she would first hit a white key and then hit a black key?

 The required probability is

Step-by-step explanation:  Given that there  are 52 white keys and 36 black keys on a standard piano. A person did not look and hit the keyboard twice.

We are find the probability that the person first hit a white key and hit a black key.

Let A and B represents the events that the person hit a white key and a black key respectively.

Then, the probabilities of events A and B are given by

Since the events A and B are independent of each other, so the probability that the person first hit a white key and hit a black key is given by

Thus, the required probability is

to determine the unit cost your would divide the total cost by the number sold.

7 bagels for $4.41       $4.41/7 = $.63 each at fresh side

5 bagels for $3.60         $3.60/5 = $.72 each at value mart

answer: the answer is b. i think hope i got it correct

step-by-step explanation: