1. The problem statement, all variables and given/known data I'm just a bit stupefied at trying to prove a cardinality. I'm not sure I have the skills, but I would like to show that the cardinalities of R (the real numbers) and the interval on (0,1) are equivalent.--to be clear, the interval here is all real numbers between (0,1). 2. Relevant equations I suppose I could show some sort of bijection between the two, but I don't know how to begin it. I do realize that I will need a more general definition than an actual formula. 3. The attempt at a solution I'm stuck here. I don't know how to begin exactly. This is not my homework problem. In fact, my homework is to show that the cardinalities of R and the interval of real numbers (1,infinity) are equivalent. Any tips would be very appreciated!