Answer:
I believe that Kevin is 6 years old now.
Step-by-step explanation:
I used the guess and check method to figure this out.
First, I began by making Daniel 1 years old, two years ago. Kevin was 4 times as old as Daniel two years ago, so he would be 4 at the time. Now, Daniel would be 3 and Kevin would be 6 years old. The statement that Kevin is three years older than Daniel would confirm this, because 6-3=3. Hope this helps, this is my first time answering:)
Answer: a) P = 0.5, b) P = 0.07
Step-by-step explanation:
Hi!
Lets call X₁ the time at which you arrive, and X₂ the time at which Bob arrives. Both are random variables with uniform density in the interval [0, 60] (in minutes). Their joint distribuition is uniform over the square in the image, with value P = 1/(60*60) = 1/3600.
a) For you to get more cake than Bob, you should arrive earlier. This event is A = { X₁ < X₂ }, the shaded triangle in the figure.The area of this event (set) is half the total area of the square, so P(A) = 0.5.
It makes sense, beacuse its equally probable for you or Bob to arrive earlier, as both have uniform density over the time interval.
b) In this case you arrive later than Bob, but less than 5 minutes later. So the event is B = { X₂ < X₁ < (X₂ + 5) } . This is the gray shaded area in b) part of the image. Its area is the difference two triangles (half square - blue triangle), then the probability is:

Divide both sides by -3, and replace
with
. Then

Factorize the quadratic in
to get

which in turn means

But
for all real
, so we can ignore the first solution. This leaves us with

If we allow for any complex solution, then we can continue with the solution we ignored:

The correct answer is <span>R(x) = 9,000[9(1.035)x + 7(1.021)x]; $170,936</span>
Need more info. What are you trying to look for?