In the town of Manh, all the residents belong to either one or the other of the town’s two fitness clubs – Giang’s House of Fitness (G) or Thu’s Wonder Gym (T). Each year 30% of the members of switch to and 25% of the members of switch to . Any other losses or gains of members by the two fitness clubs may be ignored.
a)
Write down a transition matrix representing the movement of members between the two clubs in a particular year.
In a game, enemies appear independently and randomly at an average rate of 2.5 enemies every minute.
a)
Find the probability that exactly 3 enemies will appear during one particular minute.
Question 5b
Marks: 2
b)
Find the probability that exactly 10 enemies will appear in a five-minute period.
Question 5c
Marks: 2
c)
Find the probability that at least 3 enemies will appear in a 90-second period.
Question 5d
Marks: 2
d)
The probability that at least one enemy appears in seconds is 0.999. Find the value of correct to 3 significant figures.
Question 5e
Marks: 4
e)
A 10-minute interval is divided into ten 1-minute periods (first minute, second minute, third minute, etc.). Find the probability that there will be exactly two of those 1-minute periods in which no enemies appear.
Question 5f
Marks: 4
On the next level of the game, there is a boss enemy and a number of additional henchmen to fight against.
The number of times that the boss enemy appears in a one-minute period can be modelled by a Poisson distribution with a mean of 1.1.
The number of times that an individual henchman appears in a one-minute period can be modelled by a Poisson distribution with a mean of 0.6.
It may be assumed that the boss enemy and the henchmen each appear randomly and independently of one another.
Each time that the boss enemy or any particular henchman appears, it is counted as one ‘enemy appearance’.
f)
Determine the least number of henchmen required in order that the probability of 40 or more ‘enemy appearances’ occurring in a 3-minute period is greater than 0.38. You may assume that neither the boss enemy nor any of the henchmen are able to be totally eliminated from the game during this 3-minute period.
Question 6a
Marks: 1
James throws a throws ball to his friend Mia. The height, , in metres, of the ball above the ground is modelled by the function
where is the time, in seconds, from the moment that James releases the ball.
a)
Write down the height of the ball when James releases it.
Question 6b
Marks: 2
After 4 seconds the ball is at a height of metres above the ground.
b)
Find the value of .
Question 6c
Marks: 2
c)
Find
Question 6d
Marks: 3
d)
Find the maximum height reached by the ball and write down the corresponding time .
Question 6e
Marks: 4
James then drives a remote-controlled car in a straight horizontal line from a starting position right in front of his feet. The velocity of the remote-controlled car in is given by the equation
e)
Find an expression for the horizontal displacement of the remote-controlled car from its starting position at time seconds.
Question 6f
Marks: 3
f)
Find the total horizontal distance that the remote-controlled car has travelled in the first 5 seconds.
Question 7a
Marks: 6
Consider the following system of differential equations:
(a)
Find the eigenvalues and corresponding eigenvectors of the matrix .
Question 7b
Marks: 2
(b)
Hence write down the general solution of the system.
Question 7c
Marks: 3
When , and .
(c)
Use the given initial condition to determine the exact solution of the system.