Abag contains 4 white, 3 blue, and 5 red marbles. find the probability of choosing 3 blue marbles in a row if the marbles are replaced

Ineed to know the answer right now! !

You're locked out of your house. the only open window is on the second floor, 25 feet above the ground. there are bushes along the edge of the house, so you will need to place the ladder 10 feet from the house. what length ladder do you need to reach the window?

Aclassmate thinks that solving a system by graphing gives an exact answer when the lines appear to cross at a grid point, but only an approximate answer when they don't. explain why this isn't true.