How many minutes is it before 12 noon if 40 minutes ago it was three times as many minutes past 9 a.m.?
Thanks for help.
Let the number of minutes before noon ==M
Convert hours to minutes as follows:
12 x 60 ==720 minutes
9 x 60 ==540 minutes
720 - 40 - M ==540 + 3M
680 - M ==540 + 3M
680 - 540 ==3M + M
140 == 4M
M ==140 / 4 == 35 minutes to 12:00 noon
Check: 35 minutes to 12:00 noon is: 11:25 AM
40 minutes ago from 11:25 AM ==11:25 - 40 minutes ==10:45 AM
10:45 AM ==60 + 45 ==105 minutes after 9:00 AM
3 x 35 minutes ==105 minutes after 9:00 AM - which balances
