okay let me try
0.106 g mecury in 250ml, that is 0.106g/250ml, thus 0.424g/1L. express this is ppm. that is 424ppm
when they took 1, 2 and 4 ml samples - Use C1V1= C2V2,
thus 424*1=?*100 for 1 mL standard conc = 4.24 ppm
424*2=?*100 for 2 mL standard conc = 8.48
424*4=?*100 for 4mL standard...