The Odds Are

There's a site called Randomize and you pick and flip a coin.  "You have a 50/50 chance of this coin landing on heads or tails.  This U.S. penny has been flipped 162405 times.  Why don't you give it another flip!"  You can pick from a number of coins. Or you can roll the dice, generate random integers, prime numbers, lottery numbers, and random cards.  The website specializes in randomizing different things.  It has a random quote. We think of these odds and probabilities: 50-50, 60-40 and 80-20.    How many people do you need to have a 50-50 chance of sharing a birthday? 23 people.  In a room of just 23 people there’s a 50-50 chance of two people having the same birthday. In a room of 75 there’s a 99.9% chance of two people matching. I find that I have forgotten that odds and probably are not the same:   "Odds compare one event to another event, whereas probability compares one event to both possible events. Thus, when the odds are 60 to 40, the fraction for the Odds is 60/40, but the fraction to calculate the probability is 60/100". I am really thinking about the weather - of course.  That's my focus for probability as we move into spring rain and leave winter snow behind.  We want to have 0 probability of snow wherever we go.  Not that 20% chance of snow at any given point on the map.  "So for every 10 kms you travel you will increase your odds of seeing snow by multiplying the chance of snow at each point".  So stay put and reap the 20%. Our pictures today are scenes from Pennsylvania in late January when we visited the Longwood Orchid Festival.