What is the answer I feel like this is wrong?

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?

An ulcer medication has 300 milligrams in 2 tablets. how many milligrams are in 3 tablets?

If y varies directly as x2 and y=6 when x=6, find the constant of variation.