Question

A box contains 3 blue and 2 red marbles while another box contains 2 blue and 5 red marbles. a marble drawn at random from one of the boxes turns out to be blue. what is the probability that it came from the first box?

Answer 1

First add all the numbers together to get the total number of marbles which would be 12 then make a fraction 3/12. Which can be simplified to 1/4 which if needed can be changed to a percentage of 25%. So your answer is either 1/4 or 25% depending on how your teacher would like it written.