Answer:
1/2
Explanation:
I know 1/3 < 3/8 and since we're adding 1/12, I would say the best estimate is 1/2 because A, we're adding, and B, 1/2 is really close to 1/3, and 3/8 is already bigger than 1/3 to begin with, making the sum even closer to 1/2.