I think some of the questions in the MIDI-Quiz are not so unambiguous as they shoulkd be:
-"MIDI Clock contains information about the tempo of the device that’s transmitting the message. True or false?"
In my understanding this is false, because MIDI Clock is a simple status byte without any further information 'inside'.
The tempo information is given by the MIDI Clock's timing (speed), but not by the clock data itself.
- The question containing the max length of a MIDI Cable should be asked in other words. In practice MIDI cables
can be VERY long (depending on the signal quality and the enviroment. 15 meter may be a good recommendation;
but it is simply not true, that longer cables won't work.