Answer: The winning order is:
Spike
Boris
Percival.
Step-by-step explanation:
We can write the number of steps that each one did as linear relationships of the form:
y = a*x + b
where:
a represents the slope, in this case, is the velocity of each kid.
x represents the time
b represents the steep at which each one starts.
We know that the race is completed with 99 steps.
Now, we know that in one unit of time (we do not know how long this is, and this does not matter).
Boris can run 5 steps in one unit of time
Spike can run 4 steps in one unit of time
Percival can run 3 steps in one unit of time.
Now let's write the equations for each one.
B(x) will be Boris's equation, we know that he starts from the bottom, then his equation is:
B(x) = 5*x + 0
B(x) = 5*x
Now we can find the number x needed to reach the 99 step, this is:
B(x) = 99 = 5*x
99/5 = x = 19.8
Boris needs 19.8 units of time to finish the race.
S(x) will be the equation for Spike, we know that he starts 21 steps up, then his equation is:
S(x) = 4*x + 21
Let's find the value of x such that S(x) = 99
S(x) = 99 = 4*x + 21
99 - 21 = 4*x
78 = 4*x
78/4 = x = 19.5
So Spike needs 19.5 units of time to finish the race, so he needs less time than Boris, this means that he finishes before Boris.
P(x) is the equation for Percival, we know that he starts 38 steps up, then his equation is:
P(x) = 3*x + 38
Again, we want to find the value of x such that P(x) = 99
P(x) = 99 = 3*x + 39
99 - 38 = 3*x
61 = 3*x
61/3 = x = 20.33
So Percival needs 20.33 units of time to finish the race, he is the one that needs more time, so he will be the last one to finish.
The winning order is:
Spike
Boris
Percival.
