Rolling with Advantage

Question

I was trying to figure out how to quantify the benefits of rolling with Advantage in D&D and I’m coming up short.

For anyone unfamiliar with the idea, it’s simply rolling a 20-sided die twice and taking the more favorable roll.

Correct me if I’m wrong, but with a single roll my probability of success would be:

Rolls resulting in success ÷ total possible rolls.

My question, and I apologize for the rambling, is how would I figure out the aggregate chance of success with a second roll?

In: Mathematics

Answer 1

Wouldn’t the probability of successes would be exactly the same, since the first time does not influence the result of the second.