There are 40 entries in the science fair. how many ways can they finish in first, second, and third place?

The number if marbles of different colors stored in a hat is listed below: 4 red marbles 10 green marbles 7 blue marbles. without looking in the hat, dan takes out a marble at random. he replaces the marble and then takes out another marble from the hat. what is the probability that dan takes out a blue marble in both draws?

If f(x)= sqrt4x+9+2, which inequality can be used to find the domain of f(x)?

For what values of the variable x is the expression square root of 7x+14+ square root of 7-x a real number?