It's not only the students who say silly things: Whilst providing LARS, I was asked by a pilot to confirm that the height read-out on his aircraft's squawk was within tolerance as he'd just got the aircraft back from a major service. After checking his altimeter setting and altitude, I confirmed that his height read-out was indeed in within tolerance. Another pilot (solo) on the frequency obviously thought that this was a good idea and asked me to confirm that his height read-out was also OK. "Certainly, just switch on your mode C." I said.
"Errr.... I haven't got mode C." came the reply!!!!!!!
And one more:
A call on 121.5 from an instructor who stated his position and asked if D&D could spare some time so that he could demonstrate a practise emergency to his student. No problem says D&D controller - as you've given me your position, would you like me to provide you with a steer towards a particular airfield. Good idea says the instructor, how about a steer to Earls Colne which is in my 10 o'clock, range 5 miles?