Welcome to K C Yan's Singapore Math blog!

Wanting to be updated on Singapore Math news or new Singapore Math? You have come at the right place! Please leave your comments before leaving. A googol thanks.

Singapore Math

Friday, November 11, 2011

11 Random Musings on 11/11/11

On this "auspicious date" for the superstitious, and "marriageable date" for those tying the knot, here are eleven random numerical thoughts for this year's most memorable date.


1. When Numerology Meets Biology
A possible aftermath for this year's hot date is to expect a slight increase in the birthrate this coming August—maybe some 11 percent points up for greying nations like Singapore and Japan, where the fertility rate is currently below its replacement level.


2. The Heck of a Date
Let's celebrate, or meditate on, a dozen 1's at 11 seconds past 11:11 on November 11, 2011: 11:11:11 11/11/11


3. Murder by Numbers
Health risks for both mothers and babies, resulting from induced births or Caesarean operations, as parents-to-be long for an auspicious birthdate—a union of superstition and innumeracy!


4. A Mental Stimulation
A mental calculation for lovers on a hot date: Find the value of 111111 × 111111.

Predict the patternful answer for 11111111111 × 11111111111.


5. Timely Birth, Untimely Death
What is the probability that one born on 11/11/11 will have one's last heartbeat on 12/12/12?


6.  Born on 11.11.11  Died on 11.11.11
What are the chances that someone born on 11/11/11 (2011) will also die on 11/11/11 (2111)—when he or she is a centenarian?


7. The 11:11 Phenomenon
Are you a superstitious, or faithful, believer in the numerology of the 11:11 synchronicity?

Do you wake up every night at the same time, sometimes 11:11 p.m., sometimes 1:11 a.m., 2:22 a.m., 3:33 a.m.? 

Your minor medical expenses from a minor accident: $11,111.
Your hospital room number: 1111
Date of accident: November 11

Your mileage read 111111!


8. Special Birth-dates
What percent of children (or twins or triplets) in the world would be celebrating their 11th birthday on 11/11/11?


9. A Mathematical Quickie
The product of the ages of Mr. and Mrs. Yan, and their daughters, is 111,111. If Mr. Yan is two years older than his wife, find the sum of the ages of their children. 


10. Expressing Oneself in Ones
Using 1's only and the four operations (+, —, ×, ÷), what are some ways of expressing 111111?

For example, 111111 = 11 × 111 × (111 - 11 - 11 + 1 + 1)


11. A Pseudo-Mathematical Toughie
Mrs. Ones bought a certain number of pens for $1111.11. She sold each pen at $1.21. If one pen costs more than $1.00, how much did she earn in total?

Selected Answers
9. 18      11. $200.20

© Yan Kow Cheong, November 11, 2011.