Mass of 6.022 × 10²³ atoms of Carbon = 12 g

So, Mass of 1 Carbon atom = 12/6.022 × 10²³ g

Hence, mass of 3.011 × 10²⁴ atoms of Carbon = 3.011 × 10²⁴ × 12 / 6.022 × 10²³ = 60 g