1. (10 pts.) Suppose you have a language with only 3 letters: A, B, and C, which occur with frequencies 0.7, 0.2, and 0.1, respe
ctively. The following ciphertext was encrypted by the Vigen`ere method: BABABCBCAC. Assume that the key length is either 1, 2, or 3. Find the most likely key length and determine the most likely key using the method from class. Solution: We compare BABABCBCAC with its shifts by 1, 2, and 3, looking for overlaps. There are no overlaps for a shift of 1 or 3, but there are 6 overlaps for a shift of 2. Thus we expect the key length to be 2. Looking at every other letter, we see BBBBA and AACCC for the letters in even and odd positions, respectively. Due to the overwhelming frequency of the letter A in the language, we can reasonably assume that B decrypts to to A in the first sequence and C decrypts to A in the second. This gives us the key BC.
1 answer:
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Answer:
The point of division is (5 , 8)
Step-by-step explanation:
* Lets explain how to solve the problem
- If point (x , y) divides the line whose endpoints are
and at ratio
, then
and
* Lets solve the problem
- The directed line segment with endpoints A (3 , 2) and B (6 , 11)
- There is a point divides AB two-thirds from A to B
∵ The coordinates of the endpoints of the directed line segments
are A = (3 , 2) and B = (6 , 11)
∴ is (3 , 2)
∴ is (6 , 11)
∵ Point (x , y) divides AB two-thirds from A to B
- That means the distance from A to the point (x , y) is 2/3 from
the distance of the line AB, and the distance from the point (x , y)
to point B is 1/3 from the distance of the line AB
∴ = 2 : 1
∵
∴ The x-coordinate of the point of division is 5
∵
∴ The y-coordinate of the point of division is 8
∴ The point of division is (5 , 8)
<h2>Explanation:</h2><h2 />
The complete question is shown in the figure below. As you can see one square units is well shown in the graph. So we can conclude that the distance between two consecutive points is 1 unit. If so, then we can calculate the area of the parallelogram as follows:
Then, finding CB by Pythagorean Theorem:
And:
Therefore: