Your new pet kitten is trapped in a ten foot deep hole. You need a contraption to safely rescue your poor animal. How can I solve this problem? please give me a list of ideas thank you.

The first-order reaction a→2b+c has rate constant 0.538 s−1. if the initial concentration of a is 0.867 mol l−1, what is the half-life of the reaction in seconds? remember to use correct significant figures in your answer (round your answer to the nearest hundredth). do not include units in your response.