* Seconds in a minute: There are 60 seconds in a minute.

* Seconds in five minutes: 5 minutes * 60 seconds/minute = 300 seconds

* Nanoseconds in a second: There are 1,000,000,000 (one billion) nanoseconds in one second.

* Nanoseconds in five minutes: 300 seconds * 1,000,000,000 nanoseconds/second = 300,000,000,000 nanoseconds

Therefore, there are 300 billion nanoseconds in five minutes.