A: "The time now equals quarter of the time that passed since noon till now plus half of the time left from now till tomorrow's noon."

Please express R's response in HH:MM format.

Abridged from Dudeney's " Amusements in Mathematics" (1917)

There are 1440 minutes between successive noons, so if x is the number of minutes past noon and also expresses the current PM time expressed as minutes, then:

x = x/4 + (1440 - x)/2

x = 720 - x/4

5x/4 = 720

x = 576

Expressed as HH:MM, this is 9:36.

Posted by Charlie on 2011-09-19 15:09:54