how to make a 100 mL solutino of 1.50M of NaCl

M = moles/L

solve for moles.
moles = g/molar mass.
solve for grams.
How to make it is as important. Take the calculated amount of NaCl dissolve it in some water in a volumetric flask, then make to the mark with DI water. Note that this will prepare 100 mL of SOLUTION which is not the same as adding 100 mL water to the NaCl solid.