Ricardo would swim a farther distance in 1 hour. By taking the number of miles he swam and in the fraction of the hour, you can find the answer.
Divide 5 1/4 by 3 because it took 3/5 of an hour to swim that far. That would lead to 1 3/4 for 1/5 of an hour. Now that we know this, we can multiply 1 3/4 to 5 to get how much he would swim in 1 hour which is 8 3/4
Divide 4 1/2 by 5 because it took 5/9 of an hour to swim that far. That would lead to 9/10 for 1/9 of an hour. Now that we know this, we can multiply 9/10 to 9 to get how much he would swim in 1 hour which is 8 1/10
Since 8 1/10 is less than 8 3/4, Ricardo swam farther