//------------------------------//
// The Answer 3 
// Story: Life is a Test: A Series of Pony Logic Puzzles 
// by Brony_of_Brody 
//------------------------------//

Remove all except one of the stones from the red jar and put them in the other jar.

If you choose the jar with the one red stone, you're now guaranteed to get a red one.

Odds of picking the jar with the one red stone: 50% (1/2)

If you choose the other jar, there's a 5/11 chance of picking one of the red stones from it.

Odds of picking that jar (1/2) x Odds of picking red stone from said jar (5/11) = 5/22 (approx 23%)

So adding the 2 probabilities, Cozy now has an about 73% chance of choosing a red stone.