RULE in LINE PRQ:MASS PERCENTAGE of pearlite = \(\frac{{{\rm{PR}}}}{{{\rm{PQ}}}} \times 100\)= \(\frac{{\left( {0.5\; -\; 0.008} \right)}}{{\left( {0.8\; -\; 0.008} \right)}} \times 100\)= 62.12% The closest answer is 62.5%∴ Percentage of pearlite in a slowly cooled melt of 0.5% of carbon steel is 62.5%.