please help

$2$: Your alloy contains $90\%$Sn and is at temperature $200^($@$)$C

a$)$ What phases are present in the alloy at this point?

b$)$ What are the compositions of the phases present at this point?

c$)$ What proportions of the two phases make up the alloy at this point? $($Draw a tie line and perform lever rule calculations below$)$

Phase Diagram Practice Problems: Pt$.1$

Part I: Use the Cu$-$Ag Phase Diagram for the following question

$1$: Your alloy contains $60\%$Ag and is at temperature $800^($@$)$C

a$)$ What phases are present in the alloy at this point?

b$)$ What are the compositions of the phases present at this point?

c$)$ What proportions of the two phases make up the alloy at this point? $($Draw a tie line

and perform lever rule calculations below$)$