SSC CGL 2025 Tier-I · 19 September 2025, Shift 3 · General Intelligence and Reasoning · Question 19 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 11 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.

What will come at the place of question mark 4 9 2 3 5 7 8 1 ?

(a)6
(b)3
(c)5
(d)9

Answer

Why

Correct — A.
Rule: every row, column and diagonal adds to 15 (a magic square of 1 to 9).

Row 1: 4 + 9 + 2 = 15
Row 2: 3 + 5 + 7 = 15
Row 3: 8 + 1 + ? = 15, so ? = 6

Column 3: 2 + 7 + 6 = 15 ✓
Diagonal: 4 + 5 + 6 = 15 ✓

? = 6 → option (a).

Why the others are wrong

(b)
3 — 3 makes row 3 add to 8 + 1 + 3 = 12, not 15. It also repeats the 3 already in row 2.
(c)
5 — 5 makes row 3 add to 14 and repeats the 5 at the centre. Column 3 would read 2 + 7 + 5 = 14.
(d)
9 — 9 makes row 3 add to 18 and repeats the 9 in row 1. The diagonal 4 + 5 + 9 would reach 18 too.

Concept

The picture shows a 3 × 3 grid: 4 9 2 on top, 3 5 7 in the middle, and 8 1 ? at the bottom. It is the classic magic square, the digits 1 to 9 placed so every row, column and diagonal shares one sum.

That sum is (1 + 2 + … + 9) ÷ 3 = 45 ÷ 3 = 15. Subtract the two known numbers in any line through the blank to find it.

This arrangement, 4 9 2 / 3 5 7 / 8 1 6, is known as the Lo Shu square. A second check needs no sums: the grid holds each digit 1 to 9 once, and 6 is the digit not yet placed.

Key facts

A 3 × 3 magic square of the digits 1 to 9 has magic sum 15.
Its centre is always 5.
Magic sum of an n × n square of 1 to n²: n(n² + 1) ⁄ 2.

Study next

Number grids where each row follows one operationMagic squares with two or more blanksMissing-number figures in circles and triangles

Common traps

Hunting for a product or digit rule across the row before testing sums
Trusting the row sum without a second line, a column or diagonal, through the blank

The grid comes with no instruction, so test the simplest shared rule, equal sums, across all three rows before trying anything harder.

Related PYQs

No directly related past PYQ was found.