There is a bag with only red marbles and blue marbles. The probability of randomly choosing a blue marble is 59. There are 45 marbles in total in the bag and each is equally likely to be chosen. Work out how many red marbles there must be.

There are 20 red marbles

Since the probability of randomly choosing a blue marble is 5/9, then the probability of choosing a red marble will be:

= 1 - 5/9

= 4/9

If there are 45 marbles in total, the number of red marbles will be:

= 4/9 × 45

= 20

Therefore, there are 20 red marbles.

y=mx+b

step-by-step explanation:

m is slope, b is y-intercept