The answer to your question is C, and D. The way that you get this is by multiplying. To get 20, you multiply 2/5 by 4 to get 8/20, and you multiply 3/10 by 2 to get 6/20. To get 10 as a denominator for 2/5 you multiply by 2/5 to get 4/10, and you do not have to do anything to the 3/10 because the denominator is already 10. Then you just compare the numbers on the top to determine the larger fraction.
