Cyclopropane,

C3H6 has a three-membered hydrocarbon ring structure. It undergoes rearrangement to propene. At 1000oC, the first-order rate constant for the decomposition of cyclopeopane is 9.2 s-1.
a) Determine the half-life of the reaction.
b) What percent of the original concentration of cyclopropane will remain after 4 half-lives?