The other comment is correct. You simply canNOT add odd numbers together and get an even number... ever.

You CAN, however, answer the question using 'tricks'. One of which (mentioned by knowledge-seeker) is to use decimals. There are at LEAST four other ways. Best written explanation I found:

https://www.quora.com/Mathematical-Puzzles-What-is-+-+-30-using-1-3-5-7-9-11-13-15

So.... I guess the winner would depend on which trick they used (so as to match Gaurav Agarwal's answer).

Cheerio!