$($Bonus$)$ Problem $6$: Numerical Solutions

Consider a mixture of $33\%$ n$-$pentane and $67\%$ n$-$butane at $11$ bar pressure.

a$)$ What is the composition of the first drop of liquid? $($Hint: use goal seek, solver, or MATLAB to find the solution to this problem$)$

b$)$ At what temperature is all of the vapor condensed at $11$ bar pressure?