A hypothetical two component phase diagram contain with A and B as the end members. applying lever rule you find out the temperature just above the eutectic point you have 0.69B and o.31 liquid E and temperature just below the eutectic you have 0.75B and o.25A . what will be the eutectic % of A in the eutectic composition?
Before reaching Eutectic point only B was crystalized out and i.e 0.31That means in residual liquid 0.31, mineral A liquid is 0.25 and mineral B liquid is 0.31-0.25=0.06
And at Eut...