Q31. The density of ' $x$ ' M solution (' $X$ ' molar) of NaOH is $1.12 \mathrm {~g} \mathrm {~mL} ^ { - 1 }$, while in molality, the concentration of the solution is 3 m (3molal). Then $x$ is (Given : Molar mass of NaOH is $40 \mathrm {~g} / \mathrm { mol }$ )\\
(1) 3.5\\
(2) 3.8\\
(3) 2.8\\
(4) 3.0