This is essentially the same question as https://manifold.markets/KongoLandwalker/what-is-your-intuition-about-this-p but with higher initial probability (ie. closer to 1).

We have two different independent potential events A and B.

Somebody says: "Probability of A is 0.5. Event B is two times more likely than A."

What number comes to your mind as probability of B?

1) "Multiply the absolute value". 0.5*2=1

2) "Multiply the chances". There were 50 "tickets in a hat" and only 25 of them was suitable for event A, 25 invalid. (0.5=25/(25+25)). We multiply the suitable tickets and don't touch any other.

50/(50+25)=50/75=2/3

This question is just about how you interpret the phrase "more likely".

My initial thought on reading the question, was that "twice as likely" is what are the odds that the event doesn't happen twice in a row, so (1 - (.5 * .5)) = 75%.

This preserves the intuition for smaller probabilities which roughly add together (i.e. "twice as likely" for a 1% chance would be 1.99%).