1/6 of an hour= 10 because 60mins=1hour & 60/6=10 so the sailboat travels 2 1/2 miles in 10 mins. So the complex fraction would be 2 &1/2 over 10. Hope it helps!
Step-by-step explanation:
In the picture, I hope that it's a clear solution.
12/x+5
x represents “a number” because it’s unknown and the + sign is because the words sum