Someone who can "think on their feet" is a person who has the ability to react quickly. In the case of business, a speaker will often speak extemporaneously. Perhaps an audience challenges him or her with questions, maybe hostile ones, for the speaker standing on a stage. In such a situation, someone who responds well is said to be able to "think on their feet".

"Think on your feet" means to think and react to events very quickly and effectively without any preparation. If you have good ideas and want to take decisions quickly in a difficult situation, you'd use it in these examples. "You'll be able to think on your feet when you've gone through all the mistakes." "You must be able to think on your feet if you are doing live stage shows. " "You'll have to think on your feet and avoid them." "You have to think on your feet and understand the concepts" "You have to think on your feet every single day you are in the office." "It's hard to think on your feet when you're on the spot."

an stupid answer, a wood-head peater