Answer:
composition of alpha phase is 33% B
Explanation:
given data
total composition Co = 58%
β phase Cb = 83 %
mass fractions = 0.5
solution
we will use here lever rule that is
Wα = Wβ ................1
and
Wα = Wβ = 0.5
so here we will take one side i.e left
[tex]\frac{Cb - Co}{(Cb - Ca)}[/tex] = 0.5
[tex]\frac{83-58}{83-Ca} = 0.5[/tex]
Ca = 33
so that composition of alpha phase is 33% B