I need help dudes... DO THIS ASAP AND I'LL MARK YOU THE BRAINlYLIEST!!!! PLUS this question it due in 20 mins sooo

Alex went to the store and purchased red and blue jelly beans. The ratio of red to blue jelly beans is 3 to 7. If 140 jelly beans were in the bag, how many red jelly beans were in the bag?

URGENT!!!