Hey there!
Molar mass NaCl = 58.44 g/mol
Number of moles
n = mass of solute / molar mass
n = 59.76 / 58.44
n = 1.0225 moles of NaCl
Volume in liters:
270 mL / 1000 => 0.27 L
Therefore:
M = number of moles / volume ( L )
M = 1.0225 / 0.27
= 3.78 M
Hope that helps!