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
To solve this problem we first call x = number of action figures, y = number of dolles. A system of two equations with two unknowns must be made to describe the problem. The system is the following:
(x + 1) + y = 13
1/2 * x = y.
Then solving the system we have that x = 8 and y = 4.
Since we know that the number of action figures is twice as many dolls plus one, then x = 8 + 1 = 9.
Thus,
dollos = 4
action figures = 9
Divide by 5, answer is 1/7