An enzymatic reaction is carried out at different substrate concentrations, in the absence and presence of two different inhibitors (Ia)=(Ib)=1.5 mM. The following table shows the data obtained

What kind of inhibitors are Ia and Ib?

\begin{tabular}{|c|c|c|c|} \hline Substrate (mM) & v(moles/min) & va(moles/min) & vb(moles/min) \\ \hline 0.2 & 1.67 & 0.625 & 0.83 \\ \hline 0.4 & 2.86 & 1.176 & 1.43 \\ \hline 0.8 & 4.44 & 2.11 & 2.22 \\ \hline 1.6 & 6.15 & 3.48 & 3.08 \\ \hline 3.2 & 7.62 & 5.16 & 3.81 \\ \hline \end{tabular}