Math and Time Riddles

Here is a list of riddles involving dates and time or mathematics, or both.

Riddle 0001
There are many similarities between canker sores and intrusive thoughts. In fact, canker sore is to mouth as intrusive thought is to brain. Given “canker sore” = 3, “mouth” = 9, and “intrusive thought” = 160, solve for “brain.”

Solution 0001
We are told that canker sore is to mouth as intrusive thought is to brain. Set up the proportion. Cross multiplying gives 3(brain) = 1,440. Dividing both sides by 3 gives: brain = 480.

Riddle 0002
I recorded a video at 1:55 a.m. and listened to it at 1:10 a.m. on the same day. How is this possible?

Solution 0002
It happened to be the day in the middle of autumn on which the clocks are turned back one hour. I recorded the song at 1:55, five minutes before the clocks fell back, and listened to it fifteen minutes later, which due to the time change was 1:10 instead of 2:10.

Riddle 0003
Joe was born on Saturday and John was born on Monday. Their age difference is shorter than 24 hours or 86,400 seconds. How is this possible?

Solution 0003
Their births occurred during the same weekend that daylight saving time began. Joe was born at 11:55 p.m. EST on April 6, 2002. John, being born 23 hours and 30 minutes later, was born at 12:25 a.m. EDT on April 8, 2002.