Least reactive classes on Periodic table

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?

X2 + y 2 = 36 x + y = 6 solve the system of equations.

Calculate the missing value. round the answer to on decimal place. start with 70, increase it by 21%, and end up with