Erika spent 5/6 hr on her computer visiting the history channel and the discovery channel websites. She spent 1/5 hr at the history channel website. How many hours did she spend at the discovery channel website? I came up with 19/30 hr. Am I correct?

Yes, you're right.

To find out how many hours Erika spent on the discovery channel website, we need to subtract the time spent on the history channel website from the total time spent on both websites.

Erika spent 5/6 hr in total on both websites.
Out of this, she spent 1/5 hr on the history channel website.

To calculate the time spent on the discovery channel website, we subtract the time spent on the history channel website from the total time:

Total time spent on discovery channel website = Total time spent - Time spent on history channel website
Total time spent on discovery channel website = 5/6 hr - 1/5 hr

To subtract fractions, we need a common denominator, which in this case is the least common multiple (LCM) of 6 and 5, which is 30.

Converting fractions to have a denominator of 30:
Total time spent on discovery channel website = (25/30) hr - (6/30) hr

Subtracting the fractions, we get:
Total time spent on discovery channel website = (25 - 6)/30 hr
Total time spent on discovery channel website = 19/30 hr

Therefore, your calculation of 19/30 hr for the time Erika spent on the discovery channel website is correct.