The Birthday Paradox is a well-known problem in probability theory that asks:
How large does a group of random people need to be in order for two of them to share the same birthday?
The problem is considered a paradox because the answer is counterintuitively and surprisingly small: In a group of just 23 people the chances are more than 50% (50,05%, to be exact) that two people will share the same birthday.
With 25 full-time staff members at the School of Music, it can therefore be expected that there is a more than 50% probability that at least two colleagues will have the same birthday. After examining the staff birthday list we discovered to our surprise that no less than FOUR pairs of staff members share the same birthday!
22 April ~ Ms Jana Mathee & Prof Liesl van der Merwe
3 May ~ Prof Conroy Cupido & Prof Piet Koornhof
24 June ~ Ms Thandeka Mfinyongo & Dr Michelle Pretorius
25 November ~ Ms Thembinkosi Magagula & Ms Hannelie Viviers
Furthermore, each pair of birthday buddies are of the same gender! (Nerd alert: The units in the day of the month for each date are consecutive from 2 to 5.)
Even in mathematics the staff of the School of Music are exceptional!
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References & Further reading
BetterExplained.com. 2026. Understanding the birthday paradox.
https://betterexplained.com/articles/understanding-the-birthday-paradox/
Dove, L.L. 2023. What is the birthday paradox?
https://science.howstuffworks.com/math-concepts/birthday-paradox.htm
Spencer, N. 1977. Celebrating the birthday problem. The Mathematics Teacher, 70(4):348-353. https://www.jstor.org/stable/27960843
Stewart, A. 2019. Birthday paradox. Australian Mathematics Education Journal (AMEJ), 1(3):13-15.
