SSC CGL 2024 Tier-I · 11 September 2024, Shift 1 · Quantitative Aptitude · Question 21 of 95

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 below table gives the marks out of 100 obtained by five students in four different subjects in an examination. Study the table and answer the question that follows. Student/subject → Mathematics | Physics | Biology | English Suresh — 70 | 80 | 65 | 60 Ramesh — 85 | 70 | 70 | 55 Ankith — 90 | 80 | 60 | 65 Ranjith — 95 | 70 | 65 | 60 Aryan — 75 | 65 | 65 | 70 What are the average marks obtained by all five students in Mathematics?

(a)85
(b)83
(c)84
(d)80

Answer

Why

Correct — B. Read the Mathematics column down the table, not a student's row across.

Mathematics marks: Suresh 70, Ramesh 85, Ankith 90, Ranjith 95, Aryan 75
70 + 85 = 155
155 + 90 = 245
245 + 95 = 340

340 + 75 = 415
415 ÷ 5 students = 83 → option (b).

Why the others are wrong

(a)
85 — 85 is the middle value of the Mathematics column once it is sorted — 70, 75, 85, 90, 95 — so it is the median of those marks, not their mean.
(c)
84 — 84 needs a column total of 420, five marks more than the 415 the five entries actually add up to.
(d)
80 — 80 needs a total of 400, fifteen short of 415. It is the Physics mark of Suresh and of Ankith, not an average of anything in the table.

Concept

An average is the total divided by the number of entries, so the only skill this item tests is reading the right five cells.

The Mathematics marks are 70, 85, 90, 95 and 75 — one from each student's row, all from the column headed Mathematics. They total 415 for five students, so the mean is 83.

Notice the mean lands below the middle mark of 85, because the two low scores pull the total 25 marks down while the two high ones lift it only 15.

The table also carries Physics, Biology and English columns, each with its own average — Physics totals 365 for a mean of 73.

Mathematics is what this question asks for, so the remaining three columns are there to slow you down.

Key facts

The Mathematics column reads 70, 85, 90, 95 and 75, totalling 415.
Mean = total ÷ count, so 415 ÷ 5 = 83.
The mean of 83 sits below the column's median of 85.

Study next

Weighted average when the groups being combined are of unequal sizeRecovering a missing table entry from a stated column averageComparing two subject averages in the same marks table

Common traps

Answering 85, which is the median of the column rather than its mean
Averaging one student's four subject marks instead of one subject's five students

SSC prints a small marks table and asks for one column statistic, so the arithmetic is trivial and every mark lost is a reading error.

Averages also carry Quant Q.2 of this shift, where both groups score 62, and Quant Q.10, which compares four-year average production from a bar graph.

Related PYQs

No directly related past PYQ was found.