Green.
You first must find the Least Common Denominator(LCD) of the fractions. You find that it is 20. 4/5 will turn into 16/20 because you must make it have a denominator with 20, and by doing so, you must multiply to get 20. 4×4=16, 5×4=20: 16/20. For 1/2, simply multiply by 10 to get 20 as the denominator. 1×10=10, 2×10=20: 10/20. Compare the two. You may convert the fractions to decimals to make your answer reasonable. 16/20 is clearly more than 10/20, so there is your answer.
P.S
16/20 is 0.8 as a decimal.
10/20 is 0.5 as a decimal.
Oh, and You're welcome!