Christopher swam laps everyday in the town swimming pool. he swam 45 minutes each day, 5 days each week, for 12 weeks.

45(5)=225 than multiply that by 60 because remember he only swam 5 out of 7 days a week  (12x5=60)  therefore  225x60= 13,500 minutes to convert to hours divide by 60  which will be 225 hours