[tex] \sf \: c = 3 \\ \sf \: d = 4 \\ \\ \sf \: 5cd \: = \: ?\\ \\ \sf \:5 cd \hookrightarrow \\ \sf = 5 \times (3) \times (4) \\ \sf = 5 \times 12 \\ = \underline{ \bf \: 60}[/tex]
-> Just substitute the values given for variables c & d in the equation 5cd & you'll get the answer.
