Finding black hole mass from Schwarzschild radius

[Hannahj1]

Homework Statement

a black hole has schwarzschild radius of 15.4km what is the mass of the black hole in terms of the suns mass?

Homework Equations

Rsch = 2GM/c^2

The Attempt at a Solution

I plugged values into the equation and isolated for M and it gave me a different answer. Idk how the suns mass relates to the equation/answer

 

[jedishrfu]

I think they want the ratio so you know the BH mass and you can find the suns mass and then compute the ratio.

Is it 2 solar masses or 3 or even 1/2... ?

 

[e.bar.goum]

In astronomy, "one solar mass" is a unit of mass = 1.988435×10³⁰ kilograms. The sun's mass is "one solar mass". For example, the star Arcturus has a mass of 2.3*10³⁰ kg - 1.1 solar masses

Does that help?