a) 
The average speed is equal to the ratio between the total distance (
and the total time taken (
):

the distance travelled by the trucker in the first 3 hour can be written as the time multiplied by the velocity:

So the total distance is

The total time is equal to the first 3 hours + the time taken to cover the following 20 miles in the city:

So, the equation can be rewritten as:

b) 0.50 h (half a hour)
Since we know the value of the average speed,
, we can substitute it into the previous equation to find the value of
, the time the trucker drove in the city:

Answer:
Negative
Step-by-step explanation:
That's the answer........
Step-by-step explanation:
Angle formed at the circumference of the circle is half of the angle formed at the center of the same circle.
Hence,

Answer:
10
Step-by-step explanation:
A rational number is 9.
When you multiply 0.9x10 you get the sum of 9.
9 is a rational number because it is a perfect square and an integer.
I hope this helps you understand :)