Current Attempt in Progress

Compute $($a$)$ the mass fraction of proeutectoid ferrite and $($b$)$ the mass fraction of pearlite that form in an iron$-$carbon alloy containing $0\mathrm{.}40wt\%C.$ The iron$-$iron carbide phase diagram is shown in the Animated Figure $10\mathrm{.}28.$

$($a$)$

$($b$)$