If z varies directly as x, and z =30when x=8,findz when x=4

What is the celsius temperature that is equal to 94 degrees fahrenheit using the formula f=9/5 c+32

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?

Atriangle has a side lengths of 18cm, 80 cm and 81cm. classify it as acute obtuse or right?