We can round both numbers to the nearest integer, therefore
[tex]\begin{gathered} 7.8\rightarrow8 \\ 37.86\rightarrow38 \end{gathered}[/tex]Therefore
[tex]\begin{gathered} 7.8\cdot37.86\approx8\cdot38 \\ \end{gathered}[/tex]And
[tex]8\cdot38=304[/tex]Therefore 7.8 x 37.86 is something near 300. The correct answer is the letter C.
