For the decomposition of a compound AB at 600 K, the following data were obtained: [AB] (mol dm$^{-3}$) values of 0.20, 0.40, and 0.60 correspond to rates (mol dm$^{-3}$ s$^{-1}$) of $2.75 \times 10^{-8}$, $11.0 \times 10^{-8}$, and $24.75 \times 10^{-8}$. The order for the decomposition of AB is