How do you decode a numerical cryptogram by using matrices? PLEASE HELP!?

This was hard for the RAF, and it's hard for us. Please provide some more details about the specifics of your assignment.

Possibly you mean a digraphic cipher where each pair of letters is encoded into numbers.

If a plain-text matrix is

YOU ARE DOOMED

We split it into pairs YO UA RE DO OM ED

Then convert each into a pair of numbers based on the position in the alphabet

(25,15) (21,1), etc

Then use a 2x2 matrix such as A=

(3 | 2

7 | 5)

to turn each pair into a new pair of numbers. Here's a simple example - for the first three pairs of the message, you would multiply the encoding matrix (on the left) by the message (on the right)

3 2 25 21 18

7 5 15 1 5

this gives

105 65 64

250 152 151

but to get letters, we need to take the remainder after dividing by 26. If the remainder is 0, use 26 for Z instead of 0.

the remainders are

1 13 12

16 22 21

so the beginning of the encoded message is

APMVLU

(spaces are usually omitted since they can be inferred after the message is decoded)

Let's decode this. The inverse matrix would be

5 -2

-7 3

When we multiply this by the encoded matrix, we'll get

-27 21 18

41 -25 -21

this doesn't look anything like the original except for the 18 and 21. But for the others, we can add any multiple of 26 or subtract any multimple of 26 until the numbers are in range.

Thus -27 + 52 = 25

41 - 26 = 15

and so on

we'll get our original message back.

The advantage of this method is that "encoding" and "decoding" can use the same program. The only difference is the matrix that is input.

My school doesn't have an official grading scale-professors determine the cutoff for each grade. However, we don't have A+, the highest grade you can get is an A. Most professors go with 93 or above being an A, but some have higher or lower standards depending on the difficulty of the class. I took a gen-ed acting class last semester, and a 95 or above is an A, and I'm taking Multivariable Calculus now, and a 90 or above is an A. My favorite class last semester was cell biology--it was difficult, but I learned a lot. The inner workings of a cell are fascinating. Less than 10% of students at my school live on campus, but the dorms are really plush for those who do. I go to the University of Utah, and for the 2002 Olympics the school built dorms that were first used by the athletes, but were intended to be regular dorms afterwards. The old, crappy dorms were torn down. The building I lived in last year was apartment style--there were 4 people in a "room", which consisted of 4 singles, 2 bathrooms, a kitchen, and a living room.

Decode Cryptogram