Puzzles
15 December
The arithmetic mean of a set of numbers is computed by adding up all the numbers, then
dividing the result by .
The geometric mean of a set of numbers is computed by multiplying all the numbers together, then
taking the th root of the result.
The arithmetic mean of the digits of the number 132 is .
The geometric mean of the digits of the number 139 is =3.
What is the smallest three-digit number whose first digit is 4 and for which the arithmetic and geometric means of its digits are both non-zero integers?