Daily Question #83

Today's question contributed by the one and only Shrey Goyal. Send your questions to johnywalker420@gmail.com

A and B show the most commonly occurring instances of the phenomenon, while C alone shows two such common examples. What phenomenon?
Hint : Nothing scientific!

PS : Check Quiz Bonanza #3

Uncracked!! After a very long time!

Answer : RAS (Redundant Acronym Syndrome) Syndrome

A - HIV Virus
B - ISBN Number
C - ATM Machine and PIN Number

http://en.wikipedia.org/wiki/RAS_syndrome