Counting every nth occurrence (with & without a condition)

Hi,

I have a few dozen columns of data and would like from each row to count the number of negative numbers in every 3 occurrences. E.g. in row 2 I’d want to count the negative occurences in B2, E2, H2, K2 etc.

Also, I’d like to be able to count the total number of occurences along each row, again counting every 3rd occurrence, though this time both negative and positive values.

Can someone please suggest a formula for each of these two problems?

Thanks!