The speed limit in Australia is generally 80 to 110 km/h depending on the conditions of the road. If someone in Australia is driving at a speed of 90 km/h what would their speed be in miles per hour? Show your work and round to the nearest thousand.

Rick is driving to his uncles house in greenville,which is 120 miles from ricks town .after covering x miles rick she's a sign stating that greensville is 20 miles away. which equation when solved will give the value of x. a: x+120 = 20 b: x x120 =20 c: x +20 equals 120 d: x x20= 120