Saturday, September 30, 2017

Western Leaders

Here's a freaky coincidence about World War II. If you add up the year of birth, age in 1944, year of taking power, and the number of years in office in 1944 for each of the five main leaders of the Western world during World War II, the sums are all the same.

Year of birth18741889188318821878
Age in 19447055616266
Took power19401933192219331922
Years in office411221122

Can you explain this coincidence? Click below for the answer.

Saturday, September 23, 2017

Concentric Shapes

See the image below of a square inscribed inside a circle inscribed inside a square. If the outer square has an area of 100 square inches, is there a quick way of figuring out the area of the inner square? Click below for the answer.

Saturday, September 16, 2017

Digit Frequency

If you write down all the numbers from 1 to 1000 (inclusive) which digit occurs most frequently? Which digit appears least frequently in the same range? Click below for the answers.

Saturday, September 9, 2017

Counting Chickens

If one-and-a-half chickens lay one-and-a-half eggs in one-and-a-half days, how many eggs does one chicken lay in one day? Click below for the answer.

Saturday, September 2, 2017

Number Sense

How good is your "number sense"? How many of the following can you answer without using a calculator or looking up a conversion factor?
  1. Are there more inches in a mile, or Sundays in 1000 years?
  2. Are there more seconds in a week, or feet in 100 miles?
  3. Are there more millimeters in a mile, or seconds in a month?
  4. Which is larger, multiplying all the numbers from 1 to 10, or multiplying just the even numbers from 1 to 16?
  5. Which is longer, 666 days or 95 weeks?
  6. Which is longer, 666 inches or 55 feet?
  7. Which is longer, 666 hours or 28 days?
  8. Are there more ounces in a ton or inches in a kilometer?
  9. Which is hotter, $0^{\circ}C$ or $0^{\circ}F$?
  10. Which is larger, $e^\pi$ or $\pi^e$?

Click below for the answers.