SSC CGL 2025 Tier-I · 13 September 2025, Shift 2 · General Intelligence and Reasoning · Question 21 of 100

We transcribed this text from the pictures on a candidate's response sheet for this shift; the answer is the key SSC colour-marked on that sheet. Solution last reviewed 13 September 2026.

Where this paper and its answers come from

SSC does not publish CGL question papers or a public answer key. From 2025 the candidate response sheet prints every question and option as a picture, so the text here is transcribed from those pictures for this shift and checked against them independently; where the layout carries meaning, the picture is shown as well. Each answer is the key SSC colour-marked on that sheet. SSC released a tentative key for challenge and later its final one, both only to candidates behind a login, and the sheet does not say which of the two it carries. The solutions are written by UnlockIAS.

If 'X' means '+', 'Y' means '−', 'Z' means '×', and 'W' means '÷' what is the value of the following expression? 15 W 3 X 2 Y 4=?

(a)1
(b)3
(c)5
(d)7

Answer

Why

Correct — B.
Rule: replace each letter with its sign, then apply BODMAS (÷ before + and −).

Substitute: 15 W 3 X 2 Y 4 = 15 ÷ 3 + 2 − 4
Divide first: 15 ÷ 3 = 5
Add: 5 + 2 = 7
Subtract: 7 − 4 = 3 → option (b).

Why the others are wrong

(a)
1 — 1 is what remains if the + 2 is dropped: 5 − 4 = 1. Every term counts, so 5 + 2 − 4 = 3.
(c)
5 — 5 is only the first step, 15 ÷ 3. The + 2 and − 4 still have to be applied, and together they take 2 off.
(d)
7 — 7 is what you get by swapping X and Y: 5 − 2 + 4 = 7. It is also the value before the − 4 is applied.

Concept

Letter-for-sign substitution is two tasks in order. First rewrite the expression with the real signs, then evaluate it in the usual BODMAS order: division and multiplication before addition and subtraction.

Here the rewrite is 15 ÷ 3 + 2 − 4. The division goes first, and the rest runs left to right.

Key facts

In this item X = +, Y = −, Z = × and W = ÷.
Z is defined but never used in 15 W 3 X 2 Y 4.
Addition and subtraction have equal rank and are done left to right.

Study next

Sign interchange where the four maths signs swap among themselvesChoosing the correct equation after an interchange of signsBODMAS with mixed division and multiplication

Common traps

Reading the letter X as a multiplication sign because of its shape, when here it means +
Adding 3 + 2 before dividing, which gives 15 ÷ 5 − 4 = −1, a value no option offers

16 Sep 2025, 16:00, Reasoning Q.23 sets the same letter-for-sign form, 25 B 5 C 3 D 2 A 4, keyed 7.

17 Sep 2025, 12:30, Reasoning Q.22 does it with M, N, O and P: 18 P 3 M 5 O 2, keyed 16.

Related PYQs

No directly related past PYQ was found.

Topic: Numerical Operations — all 148 SSC CGL questions on it, every solved shift.