...
What you originally asked for an what you say is the correct answer aren't
the same thing. Rows in which col C <= 29 *AND* E > 10 means rows in which
*BOTH* conditions hold. The COUNTIF formula above doesn't combine the
criteria. It gives the number of rows in col F <= 29 plus the number of rows
in col H > 10, which is neither satisfying criteria col F <= 29 AND col H >
10 nor col F >= 29 OR col H > 10.
To illustrate,
____F__H
1 2 5
2 3 6
3 4 3
=COUNTIF(F1:F3,"<=5")+COUNTIF(H1:H3,">4") returns 5, which is more than the
number of rows. Is this really what you want?
If not, then you need to use SUMPRODUCT (or equivalents).
AND criteria: =SUMPRODUCT((criterion1)*(criterion2))
OR criteria: =SUMPRODUCT(--((criterion1)+(criterion2)>0))