Expand your horizons with the diverse and informative answers found on IDNLearn.com. Discover in-depth and trustworthy answers from our extensive network of knowledgeable professionals.

A bag contains the following marbles: 3 black marbles, 6 blue marbles, 15 brown marbles, and 24 green marbles. What is the ratio of blue marbles to black marbles? Express your ratio as a fraction or with a colon.