Transcript: Intuitively we might expect a more massive star to last longer than a less massive star because it has more hydrogen to consume in the fusion process, but intuition does not work for stars because of the very steep and sharp relationship between luminosity and mass. If we want to use the analogy of a fuel tank, a large mass star does indeed have a larger fuel tank than a low mass star. However the efficiency or the rate of using that fuel is much, much faster and so the more massive star lasts far less long than the low mass star. It’s as if the most massive stars in the universe were extremely fuel inefficient gas guzzling cars that burn through their fuel at an enormous rate and don’t get very far on their tank full of gas even though the tank is large whereas the lowest mass stars in the universe are extremely gas efficient or fuel efficient. They’re miserly with their fuel, and although their fuel tank is small it lasts far longer than the gas guzzlers. Thus if we have a population of stars of different masses that form at the same time the most massive stars will die first. The least massive stars will last substantially longer.