Question

There are 3 red marbles in a bag of 12 marbles. A larger bag has a total of 26 marbles, including 7 red marbles. Are the chances of choosing a red marble from each bag the same?

Answer 1

Short answer: No

Explanation: if you bring the fractions down as low as possible, the first bag has a 1 in 4 chance of getting a red marble. The 2nd bag can't be brought down anymore because 26 and 7 do not share any common divisors.