The phase diagram of Tin $(Sn)-$ Lead $(Pb)$ alloy is given above

a$.$ What is the maximum solubility of Lead in Tin? At what temperature this is achieved?

b$.$ What is the solubility limit of Tin in Lead at $150C?$

c$.$ Describe the equilibrium solidification regime of the alloy of composition $50\%$ Tin, identifying specifically the phase compositions and approximate phase proportions existing at the temperature of $200C.$ You must show your working

d$.$ At $150C,$ comparing the strength of $5\%$ Tin alloy and $20\%$ tin alloy, which one is stronger? Explain your answer