The answer is a. A should be correct
Answer:
12-inch by 16-inch- it's the largest available and can be reduced to scale for smaller photos.
Step-by-step explanation:
-Given the dimensions 7-inch by 9-inch, 8-inch by 10-inch, and 12-inch by 16-inch:
#If Alice buys 7-inch by 9-inch and the photo turn's out to be a 8-inch by 10-inch or 12-inch by 16-inch then part of her photo will be cut off.
Hence, Don't buy.
#If Alice buys 8-inch by 10-inch and the photo turn's out to be a 12-inch by 16-inch then part of her photo will be cut off. However, if the photo is a 7-inch by 9-inch then it will fit.
Hence, don't buy.
#If Alice buys a 12-inch by 16-inch and the photo turns out to be smaller than expected the she can always print it out and trim or reduce the to scale excessive print paper to the desire dimensions.
Hence, buy the 12-inch by 16-inch since it's the largest available and can be reduced to scale for smaller photos.
Answer:
The expected number of days until prisoner reaches freedom is 12 days
Step-by-step explanation:
From the given information:
Let X be the random variable that denotes the number of days until the prisoner reaches freedom.
We can evaluate E(X) by calculating the doors selected, If Y be the event that the prisoner selects a door, Then;
E(X) = E( E[X|Y] )
E(X) = E [X|Y =1 ] P{Y =1} + E [X|Y =2 ] P{Y =2} + E [X|Y =3 ] P{Y =3}
![E(X) = (2 + E[X])\dfrac{1}{2}+ (4 + E[X])\dfrac{3}{10}+ 1 (\dfrac{2}{10})](https://tex.z-dn.net/?f=E%28X%29%20%3D%20%282%20%2B%20E%5BX%5D%29%5Cdfrac%7B1%7D%7B2%7D%2B%20%284%20%2B%20E%5BX%5D%29%5Cdfrac%7B3%7D%7B10%7D%2B%201%20%28%5Cdfrac%7B2%7D%7B10%7D%29)
![E(X) = (2 + E[X])0.5+ (4 + E[X])0.3+ 0.2](https://tex.z-dn.net/?f=E%28X%29%20%3D%20%282%20%2B%20E%5BX%5D%290.5%2B%20%284%20%2B%20E%5BX%5D%290.3%2B%200.2)
Solving for E[X]; we get
E[X] = 12
