example 10.3   
p1=21.42857MW
 p2=28.57143MW
the total load on 2 units would be 221.43MW and 228.57MW respectevily. it is easy to check that incremental cost will be same for two units at these loading.
 incremental cost of unit1 is 74.29Rs.MW,
 incremantal cost of unit 2 is 74.29Rs./MW