Question

A bag contains marbles. Some are blue and the rest are red. There are 3 blue marbles for every red marble. How many blue marbles are in the bag?​

Answer 1

Answer: Doubling the red marbles means that each 2 red marbles will be replaced by 4 red marbles. So after doubling the red marbles for each 3 blue marbles there will now be 4 red marbles, giving a new ratio of 3:4.