Gamatronics

I think this is a repeated question right?

That is indeed the right way to put it. All you need to do now is solve for v. Once you do that, remember that v=wr so use that in the equation that you solved for v so now you´ll have your answer in terms of w and r, which is the way the options are presented in the problem.

Problems A and C are indeed correct. On problem B what they´re asking you is basically the same as problem A but now with respect to the second stage. The V at the second stage you already have it, that is the answer for problem A. So you need to apply the same formula, that is V+W/(1+VW/c2), where V=v3 and W=(v1+v2)/(1+v1v2/c2).​ Substitute that W into the formula and you´ll get your answer, remember that in this case c=1 so that makes the algebra easier when solving for V (v3 in this case).