Web Analysis Ep. 5 - Searching Web Server Logs using Linux CLI

Anyone knows what is the correct value for this question:
In the access logs, how many requests were successful and resulted in a 200 HTTP status code from the identified IP address?

I've used this command:
cat access.log.* | grep -E '[^/] 200' -c

which provided me with: 342 lines of HTTP 200 but it won't accept the answer.