Find the sum or difference.
 Ken swam for 2one-half hours on Friday and 1start fraction 11 over 12 end fraction hours on Saturday. What is the total amount of time he swam these two days?
 A. start fraction 7 over 12 end fraction hour
 B. 3Start fraction 5 over 12 End fraction hours
 C. 4 hours
 D. 4Start fraction 5 over 12 End fraction hours