I have two that I can not figure out:

#1: calculate the MOLALITY of 10.00 g/L of the salt, if its molar mass is 100.0 g/mol and solution density D=1.100 g/mL

work:
10.00 g NaCl x (1mL/1.100g) x (1kg/1000 mL)= 0.00909 kg
100.0 g x (1 mol NaCl/58.4 g Nacl)= 1.7 mol
1.7/0.0090= 187 MOLALITY

#2 calculate the MOLALITY of 1.00 M solution of the salt, if its molar mass is 100.0 g/mol and solution density D= 1.200 G/mL

work:
(1000*1.000 M)/ (1000*1.2 g/mL - 100 g/mol) = .909 MOLALITY