The first one because the left bound is included [ and the right one is not )
Answer:
D. The scale factor is 1:840
Step-by-step explanation:
Make 630 ft into inches, so 7560
Then make it 9/7560, which simplifies to 1/840
Answer:
The third one or the first one
Step-by-step explanation:
Can't be +4 or -4
Each blade is 360/5=72° apart from the next blade, so you would need to rotate the top fan by at least 72° to again line up with the bottom fan.