A bag contains four red marbles, nine green marbles, four blue marbles, and three yellow marbles. If Lisa draws a random marble
from the bag, what is the probability that it will be a red, green, or blue marble?

When rates are expressed as a quantity of 1, such as 2 feet per second or 5 miles per hour, they are called unit rates. if you have a multiple-unit rate such as 120 students for every 3 buses, and want to find the single-unit rate, write a ratio equal to the multiple-unit rate with 1 as the second term.

)because it's going in order of the math sign