[tex]\qquad\qquad\huge\underline{{\sf Answer}}[/tex]
Let's find the specific heat of sample using given formula :
[tex]\qquad \tt \dashrightarrow \:Q = m \: s \triangle T[/tex]
where,
[tex]\qquad \tt \dashrightarrow \:50.9 = 12 \times \: s \times 6[/tex]
[tex]\qquad \tt \dashrightarrow \:s = \dfrac{50.9}{72} [/tex]
[tex]\qquad \tt \dashrightarrow \:s = 0.707 \: [/tex]
Therefore, specific heat of that substance is 0.707 J/g°C