Phase diagram: For an alloy of $20w{t}_t^{m}Si($see Ge$-$Si phase diagram above$),$

$($i$)$ At what temperature will solidification begin, and at what temperature will it end?

$($ii$)$ Determine the composition and amount of each phase present at $1100C.$

$($ii$)$ What will be the composition and amount of the phase or phases present at $900C?$