1
If "A2" means 6, "B3" means 8, "C4" means 10, what will "D5" mean?
A.
B.
C.
D.
Answer & Solution
The pattern involves adding 3 to the
number after the letter:
- "A2" → 2 + 4 = 6
- "B3" → 3 + 5 = 8
- "C4" → 4 + 6 = 10
For "D5":
- 5 + 7 = 12.
2
In a certain code, "D7" means 28, "F6" means 36, "E9" means 45, then what will "O4" mean?
A.
B.
C.
D.
Answer & Solution
Here's how to figure out the code:
- D (4th letter) * 7 = 28
- F (6th letter) * 6 = 36
- E (5th letter) * 9 = 45
The pattern is that the letter's position in the alphabet is multiplied by the number following it.
So, O (15th letter) * 4 = 60
3
In a pattern, if (□ + ◯) = 5, (△ + □) = 7, and (◯ + △) = 8, what will (□ + △ + ◯) equal?
A.
B.
C.
D.
Answer & Solution
From the given equations:
- (□ + ◯) = 5
- (△ + □) = 7
- (◯ + △) = 8
Now, add all three equations:
- (□ + ◯) + (△ + □) + (◯
+ △) = 5 + 7 + 8
- 2□ + 2◯ + 2△ = 20
- □ + ◯ + △ = 20 ÷ 2 = 10.
4
In a military encryption system, each letter is replaced by the next letter in the alphabet. For example, A becomes B, B becomes C, and so on. What will the word "NATION" be encrypted as?
A.
B.
C.
D.
Answer & Solution
Each letter is shifted by one
position:
- N → O
- A → B
- T → U
- I → J
- O → P
- N → O
Thus, "NATION"
becomes OBUJPO.
5
In a military cryptographic system, each letter of the word is substituted with a number according to the Polybius square. If P = 31, L = 23, A = 11, N = 34, and E = 15, what will the code for "PLANE" be?
A.
B.
C.
D.
Answer & Solution
In the Polybius square, each
letter is substituted with a number that corresponds to its position in the
grid.
For "PLANE":
- P = 31
- L = 23
- A = 11
- N = 34
- E = 15
Thus, the code for PLANE is 31
23 11 34 15.
6
During World War II, the Allied forces used the One-Time Pad cipher for secure communication. If the key word is "MILITARY" and the message is "SECRET", what would the code for "SECRET" be using a One-Time Pad cipher, where the letters are added modulo 26?
A.
B.
C.
D.
Answer & Solution
To encode the message "SECRET" using the One-Time Pad
cipher with the key word "MILITARY", we follow these steps:
- Align the key with the message:
- Message: S E C R E T
- Key: M I L I T A (only take the first 6 letters
of the key)
- Convert the letters to their corresponding positions in
the alphabet (A=0, B=1, ..., Z=25):
- S = 18
- E = 4
- C = 2
- R = 17
- E = 4
- T = 19
- M = 12
- I = 8
- L = 11
- I = 8
- T = 19
- A = 0
- Add the corresponding positions and take modulo 26:
- (18 + 12) mod 26 = 30 mod 26 = 4 → E
- (4 + 8) mod 26 = 12 mod 26 = 12 → M
- (2 + 11) mod 26 = 13 mod 26 = 13 → N
- (17 + 8) mod 26 = 25 mod 26 = 25 → Z
- (4 + 19) mod 26 = 23 mod 26 = 23 → X
- (19 + 0) mod 26 = 19 mod 26 = 19 → T
- The encoded message is:
- "EMNZXT"
7
In military communications, a cipher involves using pairs of numbers to represent letters, based on their positions in the alphabet. If A = 01, B = 02, ..., and Z = 26, what would be the code for "PLANE"?
A.
B.
C.
D.
Answer & Solution
For each letter in PLANE:
- P = 16
- L = 12
- A = 01
- N = 14
- E = 05
Thus, PLANE becomes 16 12
15 14 05.
8
A commander receives a coded message that uses a Caesar cipher with a shift of 3. The coded message is " ERPE". What does the message decode to?
A.
B.
C.
D.
Answer & Solution
A Caesar cipher with a shift of 3 means each letter is
shifted forward three positions in the
alphabet during encryption. To decrypt, we shift each letter backward three positions.
- E shifted back 3 positions is B
- R shifted back 3 positions is O
- P shifted back 3 positions is M
- E shifted back 3 positions is B
Therefore, "ERPE" decodes
to "BOMB".
9
A man finds a coded message in a newspaper article. The message is " 13 25 19 20 05 18 25". The numbers represent the position of letters in the alphabet (A=1, B=2, etc.). What is the decoded message?
A.
B.
C.
D.
Answer & Solution
To decode "13 25 19 20 05 18 25", we match each number to
its corresponding letter in the alphabet (A=1, B=2, ..., Z=26).
Decoding Process:
- 13 → M
- 25 → Y
- 19 → S
- 20 → T
- 05 → E
- 18 → R
- 25 → Y
The decoded message is: "MYSTERY".
10
A detective finds a note with the phrase "zng xlmw zmbgsr". The note is believed to have been encoded using a substitution cipher with a shift of 4 positions. What is the decoded message?
A.
B.
C.
D.
Answer & Solution
In this substitution cipher,
each letter is shifted 4 positions back:
- Z → T
- N → I
- G → S
- X → T
- L → H
- M → I
- W → L
Thus, the decoded message is This
will appear.
- 1
- 2
