Answer:
17 floors
Step-by-step explanation:
1 floor every 4 seconds.
90/4 = 22.5
40 - 22.5 = 17.5
17.5 is 17ish floors, and is the only answer that is close to 17 floors.
Hello there.
We have for a circle that:

Where:
is the measure of the arc
is the measure of the angle (radians)
is the radius of the circle
In our case, we have 
We have r = 3 cm, then:

Think these are the answers to the first few hope it helps
I think the correct answer is 64
system of inequalitities is

thats the first equation, then

and

answer is the second one