This question is popping up on smartphone and tablet screens a lot lately.Since UPSC (and especially the ocean-like syllabus that you have to cover) really gets me excited,I decided to share my own way of answering this question.I am sure some of them have solved it really well,other than Gaurav Agarwal but I would be pleased to answer this on my own!







My Solution (This is truly original and I can guarantee that you can't find a replica of this answer online.) : -

1 fortnight + 15 days + 1 day = 14 days + 15 days + 1 day = 30 days 


Update on 04th July,2015 : I have received two comments on whatsapp-forwards.blogspot.com
claiming that the solution given 'is not Maths'.Well,not to mention none of the commentators of course,could solve the problem but they had their comments to aid them nonetheless.And though there are several questions which do not have conventional answers in IAS.
For example,take this question (credit goes to gpuzzles),I know a way(correct) by which
adding 4 to 10 will give 2 ?
You have to add 4 hours to 10'o clock to get the answer and instead if you apply lame methods like bringing out a minus sign out of nowhere,which is what is the given solution on the mentioned website,I am sure UPSC is not going to appreciate you much.
An alternative solution (which is more mathematical in nature) can be 3! + 13 + 11 = 30 but from where do you get the factorial sign is the counter-question.Nonetheless,I think the solution with 1 fortnight is substantial and authentic than lame methods of bringing mathematical signs out of nowhere.

Update on 19th July : Here is an alternative solution from Jagadish Ramanna,who is a M.Tech student at East West Institute of Technology,Bangalore.
We have  x + y + z = 30 (Considering x,y,z to be random variables.)
Let x+y+z=30
then x+y+z=30 implies 
x+y+z-30= 0
divide whole by 2 
(x/2) + (y/2) + (z/2) - 15 = 0
let x=9 , y =3 , z= 3 ( prime numbers given )
(9/2) + (3/2) + (3/2) = 15
(9 + 3 + 3)/2 = 15 
therefore
9+3+3 = 30
Hence solved 

we can take x,y,z as 9,3,3 or 11,1,3 or 9,5,1 or 13,1,1

A Little Additive : The post has received quite a number of Plus Ones on Google+ and the blog is receiving traffic everyday on searches related to Gaurav Agarwal.I have even had a conversation on Twitter from a previously totally unknown person about this particular problem,it was upvoted several times on IndiBlogger and the second version including 5 blanks instead of 3 was also very well received.I hope that does a make it a little authentic from the perspective of public verdict.



We have reached 9,000+ reads on this post.Can we get it to 10,000? This would help in reinstating my interest in UPSC problems. ;) 
Thank You so much for helping us reach 50,000 hits on this post!