'Covfefe' recently appeared in a question paper for students at Kolkata’s Indian Statistical Institute. | Photo Credit: Twitter

United States President Donald Trump had sent the world into a tizzy over his mysterious “covfefe” tweet and the word has now come to bamboozle students in India.

Trump’s famous (or should we say, infamous) typo recently appeared in a question paper for students at Kolkata’s Indian Statistical Institute.

LOL. Today's exam at the Indian Statistical Institute. See Qn 5. pic.twitter.com/TrHHpyGCCP — Grieve Chelwa (@gchelwa) December 1, 2017

Your tweet now has appeared on question paper of Indian Statistical Institute. See qstn no.5. you are a laughing stock all over the world. pic.twitter.com/LjZWa5VasI — Avijit Dasgupta (@coolfrnds4u) December 2, 2017

The tweet invited many responses, with people trying to solve the riddle and on Monday, the Kolkata professor who set the question paper has revealed the solution to the Indian Express. Hazra states that answer to this question is 26^7.

The time here is not meant in the physical sense, Hazra told the Indian Express but is counted by the appearance of letters.

“The original question comes from a classical exercise in the book of D Williams called Probability with Martingales,” he wrote in a response to the daily. “It says: in a random sequence of letters, drawn independently and uniformly from the English alphabetical letters, the expected time for the first appearance of the word “ABRACADABRA” is 26^11+26^4+26.”

Hazra refers to an example to simplify the solution.

“Say, in a casino, a person starts typing randomly. Now, a series of gamblers enter the casino one after the other. While the person in question types, the first gambler comes and bets Re 1 on the first word being C. If he wins then he bets again Rs 26 on the second letter being O, otherwise he loses all the money and quits the game,” he told Indian Express.

“When the second letter is typed, another gambler comes in (who is unaware of the presence of the first gambler) and bets Re 1 on the second typed word being C. So again if this second gambler wins the bet he gets Rs 26. Each player continues betting until they lose and quit the game. This goes on and each gambler keeps on coming till the word COVFEFE appears. So if one thinks a bit then the sixth-to-last gambler will win and his total profit will be Rs 26^7,” Hazra;s response concluded.

Users across the world were left scratching their heads over "covfefe": a bizarre word apparently created by the president earlier this May. “Who can figure out the true meaning of "covfefe" ??? Enjoy!” he had tweeted later.

"Despite the constant negative press covfefe," the US leader's short tweet, now deleted, had stated.