Answer: 19 and 1/12 hours (19 hours and 5 minutes)
Step-by-step explanation: To get the answer to this problem, you have to add up the fractions. The best way to do this is to convert them into improper fractions with the same common denominator. For example, halves, thirds, and quarters have a least common denominator of 12, so that should be the number on the bottom. Five and a half can be rewritten as 11 halves, or 66 twelths (66/12). 6 and a quarter can be rewritten as 25 quarters, or 75 twelths (75/12). 7 and a third can be rewritten as 22 thirds, or 88 twelths (88/12). Now that these fractions have the same common denominator, they can be added together simply by adding the numerators and keeping the denominators. Added together, 66 + 88 + 75 equals 229, so the fraction is 229/12. Now all that's left is to devide 229 by 12, which equals 19 and 1 twelth of an hour, or 19 hours and 5 minutes