to simplify the fraction 48/64, you need to divide both the numerator and denominator by their common factors. B is correct since you can divide both by 16, C is correct since both are divisible by 8, D is correct since both are divisible by 4, and F is correct since both are divisible by 2. A, however, would be correct only if the fraction were 64/48 and E would only be correct if 9 was a factor of 48 and 12 was a factor of 64, however neither haev such factors.
The answer is 2 in 20 or 1 in 10, all you have to do is add up the total number of marbles and then have the number of yellow in the total. So 2 in 20. Hope this helps you!
