Which number cannot be expressed as a decimal? 1/3, 3.14, -3, 0/3

International calls require the use of a country code. many country codes a 3-digit numbers. country codes do not begin with a 0 or 1. there are no restrictions on the second and third digits. how many different 3-digit country codes are possible?

Acoin bank containing only dimes and quarters has 12 more dimes than quarters. the total value of the coins is $11. how many quarters and dimes are in the coin bank?

Alogical argument that is presented in graphical form using boxes and arrows is called?