Answer:
Option C
Explanation:
Let's start by simplifying option A.
7 3/4 - 1 2/4 = 7-1 + 3/4 - 2/4.
Because 3/4 and 2/4 have a common denominator, we can subtract their numerators, 3 and 2, so we have 1/4.
Now we have 6 1/4 - 2 1/3, which is equal to 4 + 1/4-1/3.
We can't subtract 1/4 and 1/3 yet because they don't have a common denominator. The least common multiple of 4 and 3 is 12, so now we have 4 + 3/12-4/12, which is 4-1/12, so we know it can't be option A.
Let's change all of the fractions in option B so that they have a common denominator. The least common multiple of 12, 6, and 2 is 12. Now, we have 9 8/12 - 1 6/12 - 4 6/12. 9 - 1 = 8, and 8 - 6 = 2, so we have 8 2/12 - 4 6/12. 8 - 4 = 4, and we have 4 2/12 - 6/12, which is less than 4, so it can't be option B.
Let's get a common denominator for all fractions in option C. The least common multiple of 3, 12, and 6 is 12, so we have 10 8/12 - 5 1/12 - 1 4/12.
10 - 5 = 5, and 8 - 1 = 7, and now we get 5 7/12 - 1 4/12. 5 - 1 = 4 and 7 - 4 = 3, so we have 4 3/12, which is the mixed number we are looking for.
Therefore, the answer is option C.