I have the formula =10/counta(E6:E15 ).
This gives me 10/10 if E6 through E15 are filled.

How do I make this formula:
=10/counta( E6:E15 but exclude the cells from this range that equal any of
the numbers in B5:B8)


Example:
=10/counta(E6:E15) would be 10/10 if E6:E15 are filled

but if E12 = B5, excel would give me 10/9 because E12 would be excluded