The problem, 229.--Plant and envelope curves: plant average cost, 230; average cost, 231; the envelope, 234.--Divisibility and economics of scale: reasons for successively lower minima, 235; the ...

The crisp new dollar bill that I have just taken from my wallet bears the serial number 24598176. It’s easy to tell that the number is exactly divisible by 2 but not by 5. Is it divisible by 3? by 4?

This article shows the application of divisibility to some complex problems that are used to form questions in examinations like CAT. We first show a problem and its detailed solution to clarify that ...