SSC CGL 2025 Tier-I · 16 September 2025, Shift 3 · General Intelligence and Reasoning · Question 17 of 75

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.

Compute√144 + ∛27 = ?

(a)14
(b)15
(c)16
(d)13

Answer

Why

Correct — B.
Rule: √ undoes squaring, ∛ undoes cubing.

Square root: 12 × 12 = 144, so √144 = 12
Cube root: 3 × 3 × 3 = 27, so ∛27 = 3
Add: 12 + 3 = 15 → option (b).

Why the others are wrong

(a)
14 — 14 is 12 + 2, which needs ∛27 = 2. But 2 × 2 × 2 = 8, so the cube root of 27 is 3, not 2.
(c)
16 — 16 is 12 + 4, which needs ∛27 = 4. But 4³ = 64, not 27. The cube root of 27 is 3.
(d)
13 — 13 is 12 + 1, which needs ∛27 = 1. But 1 cubed is 1, not 27, so the second term is 3 and the sum is 15.

Concept

A square root asks which number, multiplied by itself, gives the value. A cube root asks which number, used three times in a product, gives it.

Both values here are exact: 144 is 12² and 27 is 3³. Knowing squares up to 20² and cubes up to 10³ turns this into two look-ups and an addition.

The stem is printed as a picture: Compute √144 + ∛27 = ?. The small 3 on the second root sign is what makes it a cube root, not a square root.

Key facts

√144 = 12, because 12² = 144.
∛27 = 3, because 3³ = 27.
Nearby cubes: 2³ = 8, 3³ = 27, 4³ = 64.
Nearby squares: 11² = 121, 12² = 144, 13² = 169.

Study next

Squares up to 30² and cubes up to 15³Simplification with roots, powers and BODMASSquare roots of perfect squares from the unit digit

Common traps

Dividing 27 by 3 instead of taking its cube root, which gives 9 (and 9³ is 729)
Missing the small 3 and taking √27, which is not a whole number

Reasoning Q.25 of this shift is also straight arithmetic: the sum of 11 and 40 multiplied by 5, keyed 255.

Reasoning Q.20 of this shift prices a shopping bill, 5 erasers at ₹8 and 3 folders at ₹25, keyed ₹115.

Related PYQs

No directly related past PYQ was found.

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