Coding-Decoding Questions and Answers

Answer: B

DISTANCE is coded as STHEDDMB.

Split CALENDER into halves, CALE and NDER, and reverse each: ELAC and REDN. Then shift the letters alternately back one and forward one: E-1 = D, L+1 = M, A-1 = Z, C+1 = D gives DMZD; R-1 = Q, E+1 = F, D-1 = C, N+1 = O gives QFCO. Together: DMZDQFCO.

For DISTANCE: halves DIST and ANCE reversed are TSID and ECNA. T-1 = S, S+1 = T, I-1 = H, D+1 = E gives STHE; E-1 = D, C+1 = D, N-1 = M, A+1 = B gives DDMB. So the code is STHEDDMB; the other options each have at least one wrong letter.

Answer: C

COLD DARK WINTER is written as nee zee dee.

Compare the coded sentences. 'COLD' appears in the first two, and 'nee' is their common code word, so COLD = nee. 'IS' appears in the first and third, with common code 'pee', so IS = pee. 'COFFEE' appears in the second and third, with common code 'ree', so COFFEE = ree.

Then in the first sentence WINTER = dee (the word left after nee and pee), and in the third DARK = zee. So COLD DARK WINTER = nee zee dee. 'nee dee pee' is WINTER IS COLD, and the options with ree or pee include COFFEE or IS.

Answer: C

EAGLESTONE is coded FMHBFFOPUT. In ABACTERIAL the letters are first moved one step forward in the alphabet (A to B, B to C and so on). The word is then cut into two halves of five letters and each half is written backwards. ABACT becomes BCBDU, reversed UDBCB, and ERIAL becomes FSJBM, reversed MBJSF, giving UDBCBMBJSF. PACEMAKERS follows the same rule. EAGLE becomes FBHMF, reversed FMHBF. STONE becomes TUPOF, reversed FOPUT. Joined, the code is FMHBFFOPUT. The other options place the letters of a half in a wrong order.

Answer: A

ECONOMIC is coded NMDBHBNL. The rule works on blocks of four letters. Each letter is moved one step back in the alphabet, then the two halves of each block of four are swapped. In EARNINGS, EARN becomes DZQM, and swapping halves gives QMDZ. INGS becomes HMFR, and swapping gives FRHM, which is the given code QMDZFRHM. EDUCATED checks out the same way: TBDC and DCZS. For ECONOMIC the blocks ECON and OMIC become DBNM and NLHB. Swapping the halves gives NMDB and HBNL, so the code is NMDBHBNL. The other options differ in the order of letters inside a block.

Answer: A

MONSOON is written as MONNOOS. In SUNSHINE the first three letters SUN stay as they are and the rest, SHINE, is written backwards as ENIHS, which gives SUNENIHS. Doing the same with MONSOON: the first three letters MON stay and the remaining four letters SOON are reversed to NOOS, which gives MONNOOS. MONSOON would be the word unchanged, SOONMON would move the block of four to the front, and MONSONO reverses only the last three letters, none of which follows the pattern shown by SUNSHINE.

Answer: C

COLA is coded as DPMB. In COKE to DPLF each letter moves one place forward in the alphabet: C to D, O to P, K to L and E to F. Applying the same rule to COLA gives C to D, O to P, L to M and A to B, so the code is DPMB. BMPD moves each letter one place backward instead. DPBM keeps the right first two letters but swaps the last two, and BMDP reverses the order of the answer pairs, so neither follows the rule.

As a check, the same one-place shift applied to the other letters of the given word, K to L and E to F, reproduces DPLF, so the rule is a uniform forward shift of one for every letter.

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.