You have a bag of 12 marbles, Six of the marbles are blue, two are green, three are yellow, and one is red. If you reach into the bag and grab one marble, what is the probability that it will be red

Sound travels about 750 miles per hour. a) suppose it takes about 1.5 seconds to hear the echo. how far away is the canyon wall, in feet? for this i got 825 ft b) suppose you stand 1,925 feet from the canyon wall and sound the horn. how long will it take to hear the echo? (i'm stuck on this)