I am a new graduate student and I am about to start writing my first paper. Some of my adviser's other students have been working on similar topic to what I have been working on and he has been pushing us to combine our results into one paper. However, I feel my results could be a paper on their own. I want to start beefing up my CV so that I can get extra funding and, hopefully down the road, a research position but I am afraid that if I am only a coauthor on a paper it won't look as good as if I am the sole author (especially since I worked completely on my own for my section).
So my question is: would it be better to try and publish a paper in which I am the sole author or would it be better to try and publish a slightly better paper in which I have 2 or 3 additional coauthors? Do funding selection committees and the like give precedence to people with papers that they are sole authors over ones who have coauthors?
Edit: My field is math, in case this matters.