Coding-Decoding Questions and Answers

Answer: D

Each number is coded as the sum of its digits.

\[ 9 + 8 + 7 = 24,\quad 7 + 6 + 5 = 18,\quad 4 + 5 + 6 = 15 \]

For 465 the digits add up to

\[ 4 + 6 + 5 = 15 \]

So 465 is written as 15. The values 12, 11 and 14 do not equal the digit sum, and the code does not depend on the order of the digits, as 456 and 465 have the same digits. The answer is 15, option D.

Answer: C

The capital of India is New Delhi. In the code, New Delhi is called Ranchi, so the city that stands for the capital is Ranchi. Check the chain: Patna is called Kolkata, Kolkata is called Surat, Surat is called New Delhi, and New Delhi is called Ranchi. The question asks which city, in the code names, is the capital, so we look up what name the code gives to New Delhi, and that is Ranchi. Haridwar and Kolkata are different code names (Haridwar stands for Chennai and Kolkata for Surat). The answer is Ranchi, option C.

Answer: C

CATB is related to GERZ. In HING to LMLE the first two letters each move 4 steps forward (H to L, I to M) and the last two each move 2 steps back (N to L, G to E). BUNT to FYLR follows the same pattern: B to F and U to Y are +4, N to L and T to R are -2. Applying it to CATB gives C+4 = G, A+4 = E, T-2 = R and B-2 = Z, so the code is GERZ. HFXE, HERZ and GFXE each break the pattern at one position, for example HERZ starts with H, which is 5 steps ahead of C.

Answer: C

HIDE is coded as HJFH. In CUTE to CVVH, the letters move forward by 0, 1, 2 and 3 places: C+0 = C, U+1 = V, T+2 = V, E+3 = H. In GREAT to GSGDX the shifts are 0, 1, 2, 3 and 4: G, S, G, D, X. For HIDE the same increasing shifts give H+0 = H, I+1 = J, D+2 = F and E+3 = H, so the code is HJFH. HJFG, HJEG and HJEH differ in the last two letters, which do not follow +2 and +3.

Answer: A

AUTHOR is coded as TUAROH. In CREDIT to ERCTID the word is split into two halves, CRE and DIT, and each half is written backwards, giving ERC and TID. In PEACEFUL to CAEPLUFE, the halves PEAC and EFUL become CAEP and LUFE. For AUTHOR the halves are AUT and HOR, which reversed are TUA and ROH, so the code is TUAROH. UAHTRO, UHARTO and TURAOH reorder the letters in ways that do not reverse the two halves.

Answer: C

The common words give the digits. In 3147 and 496 the common word is friends, so friends is 4. In 496 and 615 it is family, so family is 6. In 3147 and 615 it is books, so books is 1.

From 615, family is 6 and books is 1, leaving 5 for provides. The digit 9 belongs to makes, and 3 and 7 to are and like or like and are, so only 5 is the code for provides.

Answer: C

BRIDGE is coded as RBDIEG (option C). In the examples the letters are taken in pairs and the two letters of each pair are swapped: DR becomes RD, IV becomes VI, ER becomes RE, which gives RDVIRE; and TR, IA, NG, LE become RT, AI, GN, EL, which gives RTAIGNEL.

BRIDGE splits into BR, ID, GE, and swapping inside each pair gives RB, DI, EG, so RBDIEG. The other options either swap the wrong letters or move whole blocks, which neither example does.

Answer: A

BUDGET is coded as DUBTEG (option A). BAT becomes TAB, which is BAT reversed. DOMAIN is split into two halves, DOM and AIN, and each half is reversed to give MOD and NIA, which joins to MODNIA as printed.

BUDGET splits into BUD and GET, and reversing each half gives DUB and TEG, so DUBTEG. TEGDUB (option B) swaps the halves as well, DUBGET leaves the second half unreversed, and TEGBUD swaps the halves without reversing the first, so none of these follow the pattern of the two examples.

Answer: D

LOVE is written as 54. Each letter takes the value of its place in the alphabet and the values are added. GAME is 7 + 1 + 13 + 5 = 26 and MONTH is 13 + 15 + 14 + 20 + 8 = 70, which match the two given codes. So LOVE is 12 + 15 + 22 + 5 = 54.

50, 56 and 52 do not equal the letter-value sum of L, O, V and E.

Answer: C

ARREST is written as 5-6-6-8-7-2. Compare STEADY = 7-2-8-5-0-1 and ENTRY = 8-3-2-6-1 letter by letter: S = 7, T = 2, E = 8, A = 5, D = 0, Y = 1 from the first, and E = 8, N = 3, T = 2, R = 6, Y = 1 from the second, which agree on E, T and Y. Therefore A = 5, R = 6, R = 6, E = 8, S = 7, T = 2.

The other options start with 2 (the code for T) or reverse the last letters.

The two given words share E, T and Y, and the code letters agree in both words (E = 8, T = 2, Y = 1), which confirms the letter-by-letter reading.