Coding-Decoding Questions and Answers

Answer: B

Only two pairs are correctly matched.

Pair 1, with A = 1, B = 2 and so on: C + A + T = 3 + 1 + 20 = 24. Correct.

Pair 2 reverses the alphabet, Z = 1, Y = 2, so a letter at position p gets \(27 - p\): B = 25, A = 26, T = 7, and BAT = 58, not 25. Incorrect.

Pair 3: R + A + T = 18 + 1 + 20 = 39. Correct.

The trap in pair 2 is to read B = 25 and stop; the code is the sum of all three letters.

Answer: C

A person stands on the Roof.

A person actually stands on the floor. In the code given, 'floor is called roof', so in this language the floor is named roof.

Answering 'Floor' gives the real object instead of its code name; in the code, 'floor' is the word for a door. 'Ventilator' is the code for a roof and 'Wall' is not a code word for anything in the list.

Answer: B

TRAINING is written as UQBHOHOF.

Compare SIKKIM with THLJJL letter by letter: S+1 = T, I−1 = H, K+1 = L, K−1 = J, I+1 = J, M−1 = L. The shifts alternate +1, −1.

Apply the same to TRAINING: T+1 = U, R−1 = Q, A+1 = B, I−1 = H, N+1 = O, I−1 = H, N+1 = O, G−1 = F, giving UQBHOHOF.

SQBHOHOH starts with −1 instead of +1, and UQBJOHHO and UQBJOHOH shift the first I forward to J where the pattern calls for a step back.

Answer: A

DANGER is coded as 10-7-20-13-11-24.

In MACHINE each letter's position in the alphabet is increased by 6: M (13) becomes 19, A (1) becomes 7, C (3) becomes 9, H (8) becomes 14, I (9) becomes 15, N (14) becomes 20 and E (5) becomes 11.

For DANGER: D 4 + 6 = 10, A 1 + 6 = 7, N 14 + 6 = 20, G 7 + 6 = 13, E 5 + 6 = 11, R 18 + 6 = 24.

10-7-20-16-11-24 slips on G, and the options starting 13 begin from the wrong value for D.

Answer: C

The answer is Intelligent.

The colour of ocean water is actually blue. In this code language, 'blue' is called 'intelligent', so the answer in the code is intelligent.

'Blue' is the real colour but not the coded word. 'Moon' is the code for sky, and 'bright' is the code for intelligent, which is one step too far along the chain.

Answer: B

BRIGHT is coded as 64.

The code is the sum of the letters' positions in the alphabet. EXCELLENT checks out:

\[ \begin{aligned} E{+}X{+}C{+}E{+}L &= 5{+}24{+}3{+}5{+}12 \\ {+}L{+}E{+}N{+}T &= 12{+}5{+}14{+}20 \\ \text{total} &= 100 \end{aligned} \]

\[ B{+}R{+}I{+}G{+}H{+}T = 2{+}18{+}9{+}7{+}8{+}20 = 64 \]

90, 84 and 62 do not match this sum.

Answer: C

SIMILARLY is coded as ISIMRAYLL.

Compare STRUCTURE with TSURUTERC. The first four letters are swapped in pairs: ST → TS and RU → UR. The last five letters C T U R E become U T E R C: the third, second, fifth, fourth and first of those five.

Apply the same steps to SIMILARLY. SI → IS and MI → IM; the last five letters L A R L Y become R A Y L L. Together: ISIM RAYLL. Options A and B scramble the letters in other ways, so 'None of these' is also wrong.

Answer: B

258 is coded as 157.

The code is made of two parts written side by side: the sum of all three digits, followed by the sum of the first two digits.

For 258, the digits add to 2 + 5 + 8 = 15 and the first two add to 2 + 5 = 7, giving 157. The other options do not fit the rule that produced all three given codes.

Answer: D

The code for SECTION is PQKVEGU.

The rule is: write the word backwards, then move every letter two places forward in the alphabet.

CLASS reversed is SSALC, and shifting each letter by +2 gives S→U, S→U, A→C, L→N, C→E, which is UUCNE, as given.

SECTION reversed is NOITCES. Shifting each letter by +2 gives N→P, O→Q, I→K, T→V, C→E, E→G, S→U, which is PQKVEGU.

The distractors differ only in letter order or in one letter: PQKVGEU swaps E and G, and PQLVEGU shifts I by three places instead of two.

Answer: C

TRACK is written as 48135.

Each letter of RACKET has its own digit, in order: R = 8, A = 1, C = 3, K = 5, E = 2, T = 4.

TRACK uses only these letters: T = 4, R = 8, A = 1, C = 3, K = 5, giving 48135.

24813 starts with E's digit 2, 35418 and 54312 start with C's and K's digits, so none of them matches T R A C K letter by letter.