Answer:
a) 1/27
b) 16
c) 1/8
Step-by-step explanation:
a) 
One of the properties of the exponents tells us that when we have a negative exponent we can express it in terms of its positive exponent by turning it into the denominator (and changing its sign), so we would have:

And now, solving for x = 9 we have:

b) 
This is already a positive rational exponent so we are just going to substitute the value of y = 8 into the expression

c) 
Using the same property we used in a) we have:

And now, solving for z = 16 we have:

1 km = 1000m
1 hr = 3600 s
189 km/h
189 * 1000 / 3600 m/s
189*5/18 m/s
945/18 m/s
315/6 m/s
105/2 m/s
52.5 m/s
in 10 s
52.5*10
525 m
Answer:
0
Step-by-step explanation:
The answer is 0. It shows up the most on the list. Also I know the awful Khan Academy brought you here.
Work out the number of hours in 1 year:-
1 year = 365*24 = 8760
So the number dying each hour = 31,000 / 8760 = 3.54