Hello,

I am very new to R and am just doing a course learning it. I am working with 3 categorical variables:

- adult told they had asthma
- adult still has asthma
- gender

I am trying to find out of all those that said "Yes" to "told they had asthma", how many of those said "Yes" to "still has asthma". And finally, by gender.

I am really struggling to do even the first part. Is there anyway I can filter all the "Yes" from the first variable and then find all the "Yes" in the second variable?

I tried using the filter function, but for some reason, it comes back to "0 row" as the result.

Any advice and guidance will be greatly appreciated!