document.write( "Question 908935: 3 buses leave a central station at 7am for a continuous circular route. One takes 8 minutes, one takes 9 minutes, and one takes 15 minutes. What time will they all arrive together at the central station? \n" ); document.write( "
Algebra.Com's Answer #551397 by JulietG(1812)![]() ![]() You can put this solution on YOUR website! You're looking for the least common multiple. \n" ); document.write( "Bus A arrives at the station at these minutes: 8, 16, 24, 32, 40, 48, 56, 64, 72, 80, 88, 96, etc \n" ); document.write( "Bus B arrives at the station at these minutes: 9, 18, 27, 36, 45, 54, 63, 72, 81, 90, 99, etc \n" ); document.write( "Bus C arrives at the station at these minutes: 15, 30, 45, 60, 75, 90, etc \n" ); document.write( "Take each of the \"minutes\" down to their prime factors. \n" ); document.write( "A (8) = 2 * 2 * 2 \n" ); document.write( "B (9) = 3 * 3 \n" ); document.write( "C (15) = 5 * 3 \n" ); document.write( "You'll need to use 3-2s and 2-3s and 1-5 in order to accommodate them all. \n" ); document.write( "2 * 2 * 2 * 3 * 3 * 5 = 360 \n" ); document.write( "Bus A will make 45 loops \n" ); document.write( "Bus B will make 40 loops \n" ); document.write( "Bus C will make 24 loops \n" ); document.write( " |