1°C is the temperature at noon.
What? That doesn't make sence! Any way if you mean 1997 to 2014 how many years.
Answer:

Step-by-step explanation:
you have that the average sped is given by the following formula:

The uncertainty formula for a division is given by:
(1)
Δv: uncertainty in speed
Δx: uncertainty in the distance = 0.9m
Δt: uncertainty in time = 0.7s
x: distance = 8.1m
t: time = 1.7s
You replace the values of all parameters in the equation (1):

Hence, the relation between the uncertainty in the average velocity is 0.426
M = hours driven by Maria
c = hours driven by Carlos
since we know that Carlos was driving at an average of 52 mph, then in 1 hour he drove 52 miles, in 2 hours he drove 2*52 miles in "c" hours he drove c*52 miles or
52c.
Maria on the other hand is faster and does 54 mph, in 1 hour she does 1 * 54 miles, and on 2 hours she does 2 * 54 miles and in "m" hours she does m * 54 miles or
54m.
now, we know the total amount of miles they both drove is 217, so whatever "m" and "c" are we know that
54m + 52c = 217.
we also know it took 4.1 for the whole trip, so
m + c = 4.1.

so Maria drove for 1.9 hours.
How many hours did Carlos drive for? well, c = 4.1 - m.