system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How is the 4 X 100m world record time less than 4 times the individual 100m world record?

The world record for 100m is 9.58sec. Which, I assume, means this is the fastest recorded time a person a has run a 100m distance.   


With that line of thought, you'd assume that the 4X100m would be at most as fast as the 100m record which would imply a minimum time of at least 4 X 9.58, which is 38.32 sec. However, the world record for the 4 X 100m is 36.84sec which would mean an average of 9.21sec per 100m, which is way faster than the 100m record. How is this explained?
gpt
The 4x is a relay. You have 4 different people running each lap. They carry a baton, run their 100 m then hand it off. However, when they hand it off the other person can be moving. If you watch the person taking the baton will start running with the person handing it off. Their 100 m doesn't start until the baton is handed off.

What this all means is that only the first runner in the relay has to speed up. The other runners start their 100 m already running at or near full speed. This cuts down on the time.