A box contains 7 red marbles, 5 white marbles, and 3 blue marbles. If a marble is randomly selected from the box, what is the probability that it is white? Express your answer as a fraction or a decimal number rounded to three decimal places, if necessary.

One expression below in undefined, and the other expression has a well defined value. which expression is undefined and explain why it has no value. which expression is defined? what is the value of that expression and how do you know? what is a different expression using a trig inverse function that is also undefined?

The length of each stair is 11 inches. what is the rise, r, for each stair? round to the nearest inch. 2 inches 7 inches 17 inches 24 inches

In the figure shown below, m < 40 and ab =8. which equation could be used to find x?