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

+25 = x

step-by-step explanation:

here x is the hypotenuse of a right triangle whose legs are 7 and 24.   by the pythagorean theorem, 7² + 24² must equal x²:

x² = 49 + 576 = 625.   thus, x = +√625 = +25 = x

answer: i think it is (1,-2)