standard_description: Know there is a complex number i such that i^(2) = –1, and every complex number has the form a + bi with a and b real.
problem_activity: Task
Ty took the escalator to the second floor. The escalator is 12 meters long, and he rode the escalator for 30 seconds. Which statements are true? Select all that apply.
He traveled 2 meters every 5 seconds.
Every 10 seconds he traveled 4 meters.
He traveled 2.5 meters per second.
He traveled 0.4 meters per second.
Every 25 seconds, he traveled 7 meters.


aligns: no