Handy measurements

About

NOTE: This page is a daughter page of: Programming interviews

In appearing knowledgeable and figuring out problems, it helps to know a few measurements. On this pages I've included what I consider some important stats to know (but many of which I forget).

Important Constants

• Pi:	3.1415927	(Constants: Pi)
• e:	2.7182818	(Constants: e)... base of natural logarithms = lim(0->inf) (1+1/n)^n

Handy Conversions

• 1 mile ~= 1.6 kilometers

• 1 kilogram ~= 2.2 pounds

Useful Computer Science Values

• 28	= 256 .....(one byte - unsigned int / char)
• 210	= 1,024 ............... 220 = 1 million ..... 230 = 1 billion (and so on)
• 216	= 65,536 .....(two bytes - short)
• 232	= 4,294,967,296 .....(two bytes - int)
• 264	= 18,446,744,073,709,551,626 (1.8x10^19) .....(four bytes - long)

See Also

• Handy world statistics
• Computer metrics - lists out the cost, speed and capacity of modern computer components

Links

• Wikipedia - Earth - contains stats on the earth