SSC CGL 2024 Tier-I · 10 September 2024, Shift 2 · General Intelligence and Reasoning · Question 16 of 100

Text as printed on a candidate's response sheet for this shift; answer per SSC's tentative key as marked on that sheet. Solution last reviewed 6 September 2026.

Where this paper and its answers come from

SSC does not publish CGL question papers or a public answer key. The questions and options here are reproduced as printed on a candidate's own response sheet for this shift — the Commission's text, unchanged. Each answer is SSC's tentative key as marked on that sheet; SSC allowed challenges to it and never publishes a final key. The solutions are written by UnlockIAS.

In a certain code language, ‘COWS’ is coded as ‘7935’ and ‘OILY’ is coded as ‘2568’. What is the code for ‘O’ in that language?

(a)8
(b)9
(c)5
(d)2

Answer

Why

Correct — C. You do not need the whole cipher, only the letter the two words share.

Rule: the one letter common to both words must carry the one digit common to both codes.

COWS uses the digits 7, 9, 3, 5.
OILY uses the digits 2, 5, 6, 8.

The only letter in both words is O. The only digit in both codes is 5.

So O is coded 5 — option (c).

Why the others are wrong

(a)
8 — 8 appears in the OILY code alone. If O were 8, then 8 would have to turn up among 7, 9, 3 and 5 as well, and it does not.
(b)
9 — 9 is what you get by matching letters to digits in order in COWS, giving C=7, O=9, W=3, S=5. That reading fails at once, because the code for OILY contains no 9.
(d)
2 — 2 comes from reading OILY positionally as O=2, I=5, L=6, Y=8. The same objection applies in reverse: 7935 has no 2 in it.

Concept

SSC sometimes asks for the code of a single letter rather than a whole word. That is a signal, not a shortcut being offered by accident: two words have been chosen that overlap in exactly one letter, and their codes overlap in exactly one digit.

The digits in this family of questions are not printed in the same order as the letters, so a position-by-position read is unsafe. Set intersection settles the shared letter even while the rest of the cipher stays unknown.

The question gives you no way to pin down C, W, S, I, L or Y, and it does not ask you to. Anything you decide about them would be a guess.

Key facts

COWS and OILY share exactly one letter, O, and their codes 7935 and 2568 share exactly one digit, 5.
The digits in these codes are jumbled against the letters, so the first digit need not code the first letter.
An intersection of two sets settles a single shared element without solving the rest of the code.

Study next

Coding by a fixed shift along the alphabet, as at Reasoning Q.4 in this shiftCoding in which a word's letters are rearranged before substitutionCoding where each letter is replaced by its alphabet position and the digits are then added

Common traps

Assuming the first digit codes the first letter, which gives the wrong value 9 from COWS
Trying to solve the entire cipher when only one letter has been asked for
Dismissing the shared digit as a coincidence and then guessing from position

When two given words share exactly one letter, compare the two codes as sets rather than letter by letter — the shared letter and the shared digit have to be each other.

A shift-based coding item sits earlier in this same shift at Reasoning Q.4.

Related PYQs

No directly related past PYQ was found.