Sebastion swam laps every day in the community swimming pool. he swam 45 minutes each day, 5 days each week, for 12 weeks. in that time, he swam 1,800 laps. what was his average rate in laps per hour?

He swam 1,800 laps total, in 12 weeks.

Each week, he swam  1800/12 = 150 laps, in 5 days.

Each day, he swam  150/5 = 30 laps, in 45 minutes.

His average time was  (30 laps) / (45 minutes)

                                   =  (30/45) (lap/minute)

                                   =  2/3 lap/minute .

At that rate, in one hour, he would swim

           (2/3  lap/minute) x (60 minute/hour)

       =  (2/3 x 60) (lap/hour)  =  40 laps/hour .

Let's check that:

     (40 lap/hour) x (0.75 hour/day) x (5 day/week) x (12 weeks)

   =  (45 x 0.75 x 5 x 12) x (laps)  =  1,800 laps      yay !