Jessica & George's Riddle: The red box has higher probability

[prof]

It was you, George, wasn't it? You thought this puzzle up. Did the Monty Hall problem even exist in 1986?
Nope, not until 1990. It's a puzzle that already exists in Ange's world, so I thought it'd be okay to use it.
George ran me through the answer, but I was totally lost. Anyway, I don't get the details, but in this case, the odds of the blue box having the medal are about twice the odds of the red box having it.