Write down the ratio 12:30 in the form 1:n

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?

Aramp rises 4 feet over a distance of 10 feet. what is the length of the ramp?

Ineed here’s a picture of the question