Whilst on the course you have been encouraged to look carefully at the small print of any brief and to question the way any key words can be interpreted so it isn't surprising that that word 'voucher' should stand out. Could it indeed be vouchers for the canteen, the college shop or a manicure in the hair and beauty department? Guessing and finding out is just part of the thrill of this competition.
Seriously there haven't been many entries in past years and so you are well placed to get whatever it is. Give it a go.