Suppose you have a 100.00 mL of a solution of a dye and transfer 2.00 mL of this into?

The first transfer dilutes the original solution by a factor of (2 mL)/(100 mL) = 1/50, and the second dilutes the new solution by (5 mL)/(100 mL) = 1/20. So the total dilution is by a factor of (1/50)(1/20) = 1/1000, so the original concentration was 0.000158*1000 = 0.158 M.