3/4 is greater
Explanation
You would have to make these two fractions to have the same denominator. To do this you find the least common multiple of 4 and 8, which is 8. Then, since 1/8 already has a denominator of 8, you only have to change 3/4. To do this, you times 4 and 6, and you get 6/8. All you need to do at this point is to compare 1 and 6, and obviously 6 is greater than 1. Therefore, 2/4 is greater