Assume there are approximately 5,000,000,000 people on earth. What would you estimate to be the result, if you multiply together the number of fingers on every person's left hands?

(If you cannot estimate the number, then try to guess how long the number would be.)

I estimate 10^3.5 billion; that is 1 followed by 3.5 billion zeroes.

The answer should be 5 raised to the 5 billionth power. But that is the same as 10 raised to the 5 billionth divided by 2 raised to the same exponent. Now 2^10 is approximately 1000 = 10^3, so the denominator is approximately 10^3^.5billion. So we have 10 ^5billion over 10^ 1.5 billion. Result 10 ^3.5 billion.

Posted by mark hartman on 2003-05-13 19:04:51