Scream Mountain's train of cars will pick up speed by gaining kinetic energy from a large hill. The cars will then rocket through three loops in the track, starting with a heart-stopping loop 180 feet high, another loop 90 feet high, and culminating in a loop 60 feet high. In simplest terms, what is the ratio of the heights of the three loops the cars will make? HINT: As with a ratio with two items, line up the quantities and separate them with colons. Then simplify.