Answer:
The number of possible three-digit phone prefixes that are used to represent a particular geographic area is 640.
Step-by-step explanation:
The phone prefixes used to represent a particular geographic area are a 3 digit code consisting of numbers from 0 to 9.
The prefix code are of the form: <u>x</u> <u>x</u> <u>x</u>
Condition: The first or the second place cannot take values 0 or 1.
Then the first place can be occupied by the remaining 8 digits.
Similarly the second place can also be occupied by the remaining 8 digits.
And the third place can be occupied by any of the 10 digits.
So the number of ways to construct a phone prefix for any area is:

Thus, the number of phone prefixes possible for any area is 640.
Hi
Answer in photo
NOTE: I'm not sure the answer may not be true
Good Luck
#Turkey
Looks like you got it right :) Each package contains 8 chocolates, so to find 8 containers, just multiply by 8 to get 64, which would be H.
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:


As we know, sum of interior angles of a triangle is 180°
that is ~
Hence, value of x is 9°