15 solar mass star lifetime?

Question

Can anyone give me a clue as to why a 15 solar mass star does not have a main sequence lifetime that is 15 times shorter than a 1 solar mass star.

Thanks.

Answer 1

http://instruct1.cit.cornell.edu/courses...

Answer 2

Massive stars consume hydrogen in the fusion process at a rate that is millions of times greater than that of a star like our sun, its lifetime will be in millions of years opposed to billions of years for a main sequence star.