Circle T is shown. Line PS and line RS are tangent to circle T. What is the measure, in degrees, of angle PQR

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?

The lines shown below are parallel. if the green line has a slope of -1, what is the slope of the red line?

Hector and alex traded video games. alex gave hector one fourth of his video games in exchange for 6 video games. then he sold 3 video games and gave 2 video games to his brother. alex ended up with 16 video games. how many video games did alex have when he started?