a school is deciding whether to have 30,50 or 60 minute lessons.

Question

a school is deciding whether to have 30,50 or 60 minute lessons.

regardless of which length of lesson is chosen the total teaching time remains the same.

how long is the total teaching time 

 

Answer 1

1. The question, if I understand correctly, is looking for the least common multiple of 30, 50 & 60.
2. The LCM of 30, 50 & 60 is 300.  This is the smallest number that these three numbers divide into evenly.
3. Therefore, the total teaching time is 300 minutes (5 hours).  If the school decides on 30 minutes lessons, then 10 lessons are required.  For 50 minute lessons, 6 lessons are required.  And for 60 minute lessons, 5 lessons are required.
4. Of course, there could be other answers to this problem.  For example, the total teaching time could be 600 minutes.  However, the 300 minutes represents the smallest value of total teaching time that is a solution to this problem.