John had 2/3 of his homework complete, sarah had 5/10, alex 7/8, and michelle 1/2. who completed the most of the homework assignment?

a. alex
b. michelle
c. sarah
d. john

We can either calculate each fraction and compare the results, or bring all of the fractions to a common denominator by finding the smallest common multiple for the fractions' denominators (3, 10, 8, 2), which is 3 * 2^3 * 5 = 120. Thus we must amplify each fraction so that its denominator becomes 120. 2/3 becomes 40/120, 5/10 becomes 60/120, 7/8 becomes 105/120 and 1/2 becomes 60/120. We can clearly see now that the largest of these fraction is the third (105/120). So the answer is C. Sarah.