SSC CGL 2024 Tier-I · 12 September 2024, Shift 2 · Quantitative Aptitude · Question 10 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.

Solve the following: [(2.5 + 1.5)² ÷ 4 of 1⁄2 × 8 − 1]

(a)63
(b)81
(c)27.1
(d)0

Answer

Why

Correct — A. The stem is printed as an image: [(2.5 + 1.5)² ÷ 4 of ½ × 8 − 1]. In the VBODMAS order this paper uses, 'of' is settled before ÷ and ×.

Bracket first: 2.5 + 1.5 = 4
Square it: 4² = 16
'4 of ½' = 4 × ½ = 2
Divide: 16 ÷ 2 = 8

Multiply: 8 × 8 = 64
Subtract: 64 − 1 = 63 → option (a)

Why the others are wrong

(b)
81 — 81 is 9², but the bracket totals 2.5 + 1.5 = 4, so the square that starts the chain is 16. The working never has a 9 to square.
(c)
27.1 — The only decimals sit inside the bracket, and 2.5 + 1.5 = 4 clears them at the first step. From there the arithmetic is whole-number, so a fractional answer means the bracket was never closed.
(d)
0 — This is what you get by treating 4 of ½ × 8 as one block: 4 × ½ × 8 = 16, then 16 ÷ 16 − 1 = 0. 'Of' binds the 4 and the ½ only, not the × 8 that follows it.

Concept

'Of' is not a plain synonym for '×' in SSC's simplification items. In the VBODMAS order Indian school arithmetic teaches, 'of' is resolved with the brackets — before division and multiplication.

So '÷ 4 of ½' means divide by (4 × ½), that is, divide by 2. Once the 'of' pair is collapsed the rest is ordinary left-to-right work on × and ÷, with the subtraction last.

The convention is worth stating honestly: read 'of' as an ordinary multiplication and work strictly left to right and you get 16 ÷ 4 × ½ × 8 − 1 = 15.

There is no 15 among the options, so the paper is asking for the VBODMAS reading. Answer the convention the item is testing.

Key facts

VBODMAS as SSC uses it runs Vinculum, Brackets, Of, Division, Multiplication, Addition, Subtraction.
'4 of ½' means 4 × ½ = 2, and that product is formed before the division standing in front of it.
(2.5 + 1.5)² = 4² = 16, so the decimals disappear at the very first step.

Study next

VBODMAS where 'of' sits inside nested bracketsSimplification of decimal expressions in which the bracket clears the decimalChains of × and ÷ evaluated strictly left to right

Common traps

Treating 'of' as an ordinary multiplication and working left to right, which gives 15.
Collapsing '4 of ½ × 8' into a single product, which makes the divisor 16 and the answer 0.
Squaring 2.5 and 1.5 separately instead of squaring their sum.

SSC prints these as a bare 'Solve the following' or 'Simplify' line, sometimes as a typeset image with no text stem at all, and the 'of' is the whole test.

The same 'of' notation decides 13 Sep 2024, 09:00, Quant Q.15 ('60 ÷ 2 of 6', '600 ÷ 25 of (2 × 3)') and 25 Sep 2024, 12:30, Quant Q.23 ('3 of (25 − 2 × 10)').

Related PYQs

No directly related past PYQ was found.