Counting Formula

[Karen615]

I have a column (A) that lists different schools.
Then in column B, I have a list of different students who attend these schools.
Then there are three columns for tests.


Column D
Column E
Column F
Each student has to have all 3 tests completed.
If the student completed the test, there's a "Yes" in the column. If they did not, there's a "No" in the column.
Some could have completed all three tests, some could have completed only one test and not the other two - for example.
I have to count how many students have taken all 3 tests.
Then in another column, I have to count how many students have not completed all three tests. (So, there could be one, two or three "No" in any of the columns. What's the best way to handle this?
Thank you in advance