Question 25552
I'm not sure what Brians sisters wages are,what you have here does not really 
make sense.
I started the equation for you, maybe you can do the rest?
Let x = what Brian earns pumping gas
2x = what he makes as a tutor;
so the equation would be;
x+2x=150+?(2x)
Just plug in what his sister makes where I have the ? and you should be able to get the answer.
=)