Answer:
22 miles per hour
Step-by-step explanation:
we know that
The speed is the ratio of distance by the time
Let
d -----> distance in feet
t ----> time in seconds
s ----> the speed in ft/sec

we have

substitute


Remember that


Convert ft/sec to mi/h

well, in short, the students and chaperones are at a 2 : 9 ratio, and we know there are 171 students, how many chaperones then, so long they maintain a 2:9 ratio?

Significant figures tells us that about how may digits we can count on to be precise given the uncertainty in our calculations or data measurements.
Since, one inch = 2.54 cm.
This is equivalent as saying that 1.0000000.. inch = 2.540000... cm.
Since the inch to cm conversion doesn't add any uncertainty, so we are free to keep any and all the significant figures.
Since, being an exact number, it has an unlimited number of significant figures and thus when we convert inch to cm we multiply two exact quantities together. Therefore, it will have infinite number of significant figures.
80 multiplied by 0.6 = 48
80-48=32
Answer=32 Books are nonfiction
The answer to your problem is 11