SSC CGL 2024 Tier-I · 10 September 2024, Shift 1 · Quantitative Aptitude · Question 25 of 98

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 10 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.

The value of 15 ÷ 3 of 2 × 2 + 9 ÷ 18 of 2 × 4 − 4 ÷ 8 × 2 is:

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

Answer

Why

Correct — A. The stem is an image: the value of 15 ÷ 3 of 2 × 2 + 9 ÷ 18 of 2 × 4 − 4 ÷ 8 × 2.

Rule: 'of' is cleared before ÷ and × — it belongs with the bracket step, not with ordinary multiplication.

Block 1: 3 of 2 = 6, so 15 ÷ 6 × 2 = 2.5 × 2 = 5

Block 2: 18 of 2 = 36, so 9 ÷ 36 × 4 = 0.25 × 4 = 1

Block 3: no 'of' here, so left to right — 4 ÷ 8 × 2 = 0.5 × 2 = 1

Total = 5 + 1 − 1 = 5 → option (a).

Why the others are wrong

(b)
2¾ is below the opening block on its own. 15 ÷ 3 of 2 × 2 already comes to 5, and the last two blocks cancel each other, 1 − 1 = 0, so the total cannot drop under 5.
(c)
7¾ needs the middle block to be worth 3¾. With 'of' cleared first, 18 of 2 = 36 and 9 ÷ 36 × 4 = 1, which is what leaves the total at 5.
(d)
8 — 8 is what skipping 'of' in the middle block gives: 9 ÷ 18 × 2 × 4 = 4 in place of 9 ÷ 36 × 4 = 1. That one slip adds 3 and turns 5 into 8.

Concept

'Of' is not a synonym for ×. In the BODMAS order SSC applies, 'of' is resolved with the bracket step, ahead of division: 3 of 2 becomes 6 before the 15 is divided by anything.

Once every 'of' is cleared, ÷ and × rank equally and run left to right, then + and − run left to right in their turn.

The word only bites where a division sits in front of it. In 8 × 3 of 2 the reading makes no difference at all, but in 15 ÷ 3 of 2 it is the difference between 2.5 and 10.

Two of the four options are printed as images of mixed fractions, 2¾ and 7¾, so the plain text of the stem shows only the whole-number choices.

Both fractional options are baits for a half-finished division, and neither is reachable once the three blocks are evaluated as 5, 1 and 1.

Key facts

In BODMAS as SSC applies it, 'of' is cleared with brackets, before division and multiplication.
After 'of' is cleared, ÷ and × have equal rank and are applied left to right.
15 ÷ 3 of 2 is 15 ÷ 6 = 2.5, not 5 × 2 = 10.
+ and − also rank equally and run left to right, so a leading minus does not jump the queue.

Study next

BODMAS on decimals, where the same order applies with no 'of' in sightVinculum and nested brackets, the step that outranks 'of'Simplification mixing 'of' with fractions in the same expression

Common traps

Treating 'of' as plain multiplication and running everything left to right, which gives 23.
Clearing 'of' in one block and forgetting it in the other, which lands on 8.
Doing all multiplications before all divisions, so 4 ÷ 8 × 2 becomes 4 ÷ 16 = 0.25.

The plain BODMAS drill without any 'of' is set at 9 Sep 2024, 12:30, Quant Q.24, where 21 − 4.9 ÷ 7 + 3.9 × 0.4 + 0.9 comes to 22.76 on left-to-right rules alone.

The 'of' is what this stem adds on top, and it is where the marks go.

Related PYQs

No directly related past PYQ was found.