This is more of a math problem than a chemistry problem. We know that each tablet is 250 mg. The problem specified that there are 2 tablets making the final weight to be 500 mg. We can also view this as individual tablets. The Vitamin B6 in one tablet is 250. (0.4) = 100 mg. The other tablet would also have 100 mg of Vitamin B6. Two tablets will then have 200 mg of Vitamin B6. Also, 500 (0.4) is also 200 mg.
