What is the approximate main-sequence lifetime for a heavyweight star of $20 M_{\odot}$?

Answer

As little as 10 million years

A very massive star, such as one of $20 M_{\odot}$, can exhaust its core hydrogen in a very short period, potentially as little as 10 million years.

What is the approximate main-sequence lifetime for a heavyweight star of $20 M_{\odot}$?
astronomylife expectancystarmassive star