How many minutes before 12 noon is it if 72 minutes ago it was twice as many minutes past 9am?

Answer 1

It is 36 minutes before noon, or 11:24 am.

This is how I got it...

Change all hours into minutes by first multiplying them by 60. For example, 1 o'clock would be (1) (60) or just 60.

Noon or 12 = 720 and 9am = 540

Now for X.

X will be current time in minutes before noon and that equals noon-x or 720-x.

Now, 72 minutes ago was current time... minus 72

That make the equation 720-x-72

Those minutes have to be twice as many past nine so you can write 540+2x

Now, those two equations have to balance so 720-x-72=540+2x

after you subtract 540 from both sides and add x to both sides, you are left with 108= 3x

divide both sides by 3 and BOOM...36

36 minutes before noon is 11:24

Now to check...

11:24 is 2hrs or (120 minutes) + 24 minutes past 9

144 minutes

11:24 minus 72 minutes (1hr + 10 minutes) is 10:12

from 9 until 10:12 is

72 minutes

(2) (72)= 144.... It checks out.