An alloy of $30wt\%Pb$ and $70wt\%Sn$ is slowly cooled from $250C$ to $27C($see Fig. given below$).$

$($a$)$ Is this alloy hypoeutectic or hypereutectic?

$($b$)$ What is the composition of the first solid to form?

$($c$)$ What are the amounts and compositions of each phase that is present at $183C+T?$

$($d$)$ What is the amount and composition of each phase that is present at $183C-T?$