Assume one of your favorite activities is mountain climbing. When you go mountain climbing, you have several safety devices to keep you from falling. You notice that attached to one of your safety hooks is a reliability rating of 97%. You estimate that throughout the next year you will be using this device about 100 times.

Does a reliability rating of 97% mean that there is a 97% chance that the device will not fail any of the 100 times? why?
How much safer would it be to use a second safety hook independent of the first?