Suppose, a family has two or three children. Will they have the same birthday? It happened in Great Briton. In 2010, Jennifer and Briss Allah were expecting their third child. They were also preparing to celebrate the birthday of their two children, Adam and Najla on 7th October.
While Mum Jennifer was blowing up balloons for the upcoming celebrations, she felt something in her stomach and realized that her contractions had begun. She could not believe it. The unthinkable was about to happen. The family's third child, Sami, was also born on 7th October. The "daily mail" proclaimed,' Happy birthday to you ... and you... and you too. Couple's three children born on the same date'.
An event such as this occurring is mindboggling. But statistically, it can happen. Let us see the little math behind it.
The probability of first
child born on any day = 1
The probability of the second
child born on same day =1*1/365
The probability of third
child born on the same day too =1*1/365*1/365=1/133225
That is, the chance for a family to have three children born with the same birthday is 1 in 133225.
Remember, A chance for getting a head in a coin toss is 1 in 2 or 1/2. If you toss a coin 10 times, you will get 5 heads.
That is 10*1/2 =5
similarly,
In the UK, there are around a million families with three children under eighteen, hence,
1 million *1/133225=7.5
We can expect around seven of these families to have all three children share the same birthday. On an individual level, we often think about how unlikely it would happen to us. "But with a large enough sample, any outrageous thing is likely to happen".
This example once again proves that, in the case of large numbers, any miracle can happen.