In a code language, TABLE is written as UDCMF. How will CHAIR be written?

Correct — A.
Rule: shift by position: +1, +3, +1, +1, +1.

TABLE → UDCMF: T + 1 = U, A + 3 = D, B + 1 = C, L + 1 = M, E + 1 = F.

CHAIR: C + 1 = D, H + 3 = K, A + 1 = B, I + 1 = J, R + 1 = S
→ DKBJS, option (a).

Why the others are wrong

• (b)
  EJCKS — EJCKS moves C to E, a shift of +2. The first letter of TABLE moves only +1 (T → U), so CHAIR must start with D.
• (c)
  DJCKR — DJCKR leaves R unchanged at the end, but E → F in TABLE shows the last letter moves +1. It also moves H only +2, to J.
• (d)
  DJBKR — DJBKR moves H to J, a shift of +2, but the second letter moves +3 (A → D in TABLE). H + 3 is K, so the second letter must be K.

A letter-shift code moves each letter a set number of places along the alphabet. Here the shift depends on the letter's position in the word, not on the letter itself.

That is why A becomes D in TABLE, where it is 2nd, but B in CHAIR, where it is 3rd. Read the shift for each place off the example, then apply the same five shifts to the new word.

Key facts

• Shifts read off TABLE → UDCMF: +1, +3, +1, +1, +1.
• H is the 8th letter, so H + 3 = K, the 11th.
• The shift belongs to the position: A → D in 2nd place, A → B in 3rd place.

Common traps

• Reading A → D as a letter swap and turning CHAIR's A into D, when the shift belongs to the 2nd place
• Stopping at the first letter: D starts options (a), (c) and (d), so the second letter, H + 3 = K, is what decides

No directly related past PYQ was found.