We purchased a workbook that uses colons when representing probabilities. For example, this workbook says that the probability of getting heads when flipping a coin is 1:2.

Is it okay to use the colon in this situation? My first reaction was that was not correct. It reminds me of odds, or 1 option for the first outcome and two options for the second outcome so a total of three outcomes.

What do you think? Would greatly appreciate your input.

Thank you.