$\begin{array}{1 1}\text{ a)2-iodo 2-methyl butane reacts faster than t-butylchloride}\\ \text{
b)Ethyl iodide reacts faster than 2-bromo 2-methyl butane} \\ \text{
c)n-Propyl bromide reacts faster than 3-bromo cyclohexane
} \\ \text{
d)Cyclohexyl bromide reacts faster than methyl iodide.}\end{array} $
