Apparent magnitude of a binary star system

[~ZeroPoint~]

Homework Statement

A binary star system consists of a hot main sequence star (m=0.5m) and a red giant (m=1.2m), the parallax of the system is p=0.0012". Calculate the apparent magnitude of the system.

Homework Equations

I have b1/b2 = 2.512^(m2-m1) and p=1/r

The Attempt at a Solution

I've already calculated the distance from the system to the Earth (~833.65pc) and I know that I can't simply add the apparent magnitudes.

 

[Spinnor]

Looks like you need to convert magnitudes into intensities and then add the intensities, see,

https://www.google.com/webhp?hl=en#...w.,cf.osb&fp=2ddf388403c0c5d8&biw=734&bih=439