What is the molarity (M) of 60.00 g NaOH in 250 mls of solution? (Molar mass NaOH = 40g/mole?

Find the number of moles of NaOH you have

moles = mass / Molar mass

moles = 60 g / 40.00 g/mol = 1.50 moles

Now find the concentration in moles / L

C = moles / Vol (L)

C = 1.50 moles / 0.250 L = 6 moles / L