Clock never showing right time might be preferable to the one showing right time twice a day

watch

What clock did you have in mind? If it's a digital watch the problem, I am afraid, does not make a lot of sense. I've been thinking about old-fashioned watch. No functioning watch is absolutely accurate. So one can say no regular watch actually shows absolutely right time. On the other hand, the watch that stopped will show the right time twice a day. Which one would you prefer?

The progress has its downside. Probably in a while not many people will remember or have heard about a regular (what then will be regular?) watch. The late Isaac Isimov once asked How would you then explain what is the positive (counterclockwise) or negative (clockwise) direction?

So while we know what we are talking about, here are a few "regular" clock problems.

  1. Besides 12 o'clock, at what other times of day do the hands meet?
  2. When are the hands pointing in opposite directions?
  3. At what time of day does the line from 6 to 12 bisect the angle between the hands?
  4. For a clock, it takes three seconds to strike three. How long will it take for the same clock to strike seven?

|Contact| |Front page| |Contents| |Did you know?| |Store|

Copyright © 1996-2013 Alexander Bogomolny

 42851000

A math books store at a unique math study site. Shopping at the store helps maintain the site. Thank you.
Terms of use
Awards
Interactive Activities

CTK Exchange
CTK Wiki Math
CTK Insights - a blog
Math Help
Games & Puzzles
What Is What
Arithmetic
Algebra
Geometry
Probability
Outline Mathematics
Make an Identity
Book Reviews
Stories for Young
Eye Opener
Analog Gadgets
Inventor's Paradox
Did you know?...
Proofs
Math as Language
Things Impossible
Visual Illusions
My Logo
Math Poll
Cut The Knot!
MSET99 Talk
Old and nice bookstore
Other Math sites
Front Page
Movie shortcuts
Personal info
Privacy Policy

Guest book
News sites

Recommend this site

Sites for parents

Education & Parenting

Search:
Keywords:

Google
Web CTK