In a parallel universe when Neil Armstrong landed on the moon, he found it to be inhabited by a tribe of humanoids. He discovered that:
a) they were all married
b) the husbands of 10 of the wives were unfaithful
c) Each wife knew whether or not any other wife's husband...
Two impatient people agree to meet up sometime between 3pm and 4 pm, in the era before mobile phones, just near Nelson's Column in London. They are so impatient they will only wait 15 minutes before leaving. What is the probability they actually meet up?