Thank you, this chimes with what MarkK wrote and i've tested and it gives me the count I need.
So would that second bit be:
select chkbox1, chckbox2, chckbox3, chkbox4, chkbox5, count(*)
from table
group by chkbox1, chckbox2, chckbox3, chkbox4, chkbox5
or have I misunderstood?