I wonder if you know…

I do not know how many millions of people live in Calcutta, but I know it is well in excess of 14 million.

One day, a friend, M, met us in London. He told us that a mutual friend, D, was married to a woman born in Calcutta. As my wife went to school in that city, M said to her: ” You might know D’s wife.”

My wife replied: “Do you realise how many people live in Calcutta, M?”

Then after a moment, she asked; “What is her name?”

M mentioned a name. Hearing this, my wife answered: “She was a year junior to me at school.”

I thought it was amazing how small the world can seem even when a city as huge as Calcutta is being discussed.

Strange coincidence

white and blue floral table lamp


My mother’s birthday was the 15th of October. My good friend, the late Michael Jacobs, a fine author, was also born on that day, but many years later. Michael’s mother, the late Maria-Grazia, was born on the 8th of May. I was born on the same day, but many years later.

The chance of two people sharing the same birthday is quite small. It is 1 in 365 or 0.0028. Things get more interesting when one considers a group of people. In a room of 23 people, the chances that two people share a birthday is 0.5 or 50%, and when there are 75 people the probability increases to 0.99 or 99% (see: https://betterexplained.com/articles/understanding-the-birthday-paradox/ and https://en.wikipedia.org/wiki/Birthday_problem).  

I have no idea how to calculate the probability that my mother and my good friend share the same birthday AS WELL AS his mother and me sharing the same birthday. It is too long since I studied statistics and probability at school!Even then, I doubt I could have worked it out.



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