Quantitative Aptitude

Averages — Practice MCQs for CCAT

20 Questions Section A: Fundamentals Quantitative Aptitude

Practice 20 Averages multiple-choice questions designed for CDAC CCAT exam preparation. Click "Show Answer" to reveal the correct option with detailed explanation.

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Q1.
The average of 5 numbers is 20. If one number is excluded, the average becomes 18. Find the excluded number.
A24
B26
C28
D30
Show Answer & Explanation

Correct Answer: C — 28

Sum = 5×20 = 100. New sum = 4×18 = 72. Excluded = 100-72 = 28.

Q2.
The average age of 30 students is 15 years. If the teacher's age is included, the average increases by 1. What is the teacher's age?
A40 years
B44 years
C46 years
D50 years
Show Answer & Explanation

Correct Answer: C — 46 years

Sum of students = 450. New sum = 31×16 = 496. Teacher = 496-450 = 46.

Q3.
The average of first 5 multiples of 3 is:
A8
B9
C10
D11
Show Answer & Explanation

Correct Answer: B — 9

Multiples: 3,6,9,12,15. Sum = 45. Average = 45/5 = 9.

Q4.
The average of 11 numbers is 50. The average of first 6 is 48 and last 6 is 52. Find the 6th number.
A48
B50
C52
D54
Show Answer & Explanation

Correct Answer: B — 50

Sum of 11 = 550. First 6 = 288, Last 6 = 312. 6th = 288+312-550 = 50.

Q5.
The average weight of 8 persons increases by 2.5 kg when a new person comes in place of one weighing 65 kg. Weight of new person?
A75 kg
B80 kg
C85 kg
D90 kg
Show Answer & Explanation

Correct Answer: C — 85 kg

Increase in sum = 8×2.5 = 20. New person = 65+20 = 85 kg.

Q6.
The average of 6 numbers is 30. If one number is removed, the average becomes 28. Find the removed number.
A38
B40
C42
D44
Show Answer & Explanation

Correct Answer: B — 40

Sum = 180. New sum = 5×28 = 140. Removed = 180-140 = 40.

Q7.
A batsman has an average of 40 runs in 10 innings. How many runs must he score in the next innings to increase his average by 2?
A52
B58
C62
D68
Show Answer & Explanation

Correct Answer: C — 62

New average = 42 for 11 innings. Total = 462. Previous = 400. Needed = 62.

Q8.
The average of 5 consecutive odd numbers is 21. The largest number is:
A23
B25
C27
D29
Show Answer & Explanation

Correct Answer: B — 25

For consecutive odds, average = middle number = 21. Numbers: 17,19,21,23,25.

Q9.
The average marks of three batches of 55, 60, and 45 students respectively is 50, 55, and 60. Find overall average.
A54.5
B54.68
C55
D55.25
Show Answer & Explanation

Correct Answer: B — 54.68

Total marks = 2750+3300+2700 = 8750. Total students = 160. Avg = 54.68.

Q10.
The average of A and B is 45. The average of B and C is 50. The average of C and A is 55. Find A.
A40
B45
C50
D55
Show Answer & Explanation

Correct Answer: C — 50

A+B=90, B+C=100, C+A=110. Adding: 2(A+B+C)=300, so A+B+C=150. A=150-100=50.

Q11.
The average of 10 numbers is 23. If each number is increased by 4, the new average is:
A23
B25
C27
D29
Show Answer & Explanation

Correct Answer: C — 27

When each number increases by 4, average also increases by 4. New average = 23+4 = 27.

Q12.
Average of 20 observations is 45. It was later found that one observation 78 was wrongly noted as 48. Correct average is:
A46.5
B47
C47.5
D48
Show Answer & Explanation

Correct Answer: A — 46.5

Increase = 78-48 = 30. New sum increases by 30. New average = 45 + 30/20 = 46.5.

Q13.
The average of first 7 multiples of 7 is:
A21
B28
C35
D42
Show Answer & Explanation

Correct Answer: B — 28

Multiples: 7,14,21,28,35,42,49. Average = 196/7 = 28. Or average = (first+last)/2 = (7+49)/2 = 28.

Q14.
In a cricket match, average of 5 batsmen is 36. If the 6th batsman scores 55, new average is:
A38.5
B39.17
C40
D41.5
Show Answer & Explanation

Correct Answer: B — 39.17

Total = 5×36 + 55 = 235. Average = 235/6 = 39.17.

Q15.
Average age of A, B, C, D five years ago was 45. Average age now after including E is 49. Age of E is:
A45
B50
C55
D60
Show Answer & Explanation

Correct Answer: A — 45

Sum of A,B,C,D now = 4×50 = 200. Sum of 5 now = 5×49 = 245. E = 45.

Q16.
Average salary of 19 workers is ₹5000. Average salary of 12 male workers is ₹4500. Average salary of female workers is:
A₹5500
B₹5714
C₹5857
D₹6000
Show Answer & Explanation

Correct Answer: C — ₹5857

Total = 95000. Males = 54000. Females = 41000. Female avg = 41000/7 = 5857.

Q17.
Average of 10 numbers is 0. At most how many numbers can be greater than 0?
A0
B5
C9
D10
Show Answer & Explanation

Correct Answer: C — 9

At most 9. If 9 are positive, 1 must be negative to make sum 0. All 10 positive is impossible.

Q18.
The average weight of 3 boys A, B, C is 54 kg. When D joins, average becomes 53 kg. If E (weight = D+3) replaces A, average becomes 51 kg. Weight of A is:
A60 kg
B64 kg
C68 kg
D72 kg
Show Answer & Explanation

Correct Answer: A — 60 kg

ABC = 162. ABCD = 212, so D = 50. BCDE = 204. BCD = 50+162-A. BCE + E = 204...

Q19.
A vehicle travels 40 km at 20 km/h, 40 km at 40 km/h, and 40 km at 60 km/h. Average speed is:
A30 km/h
B32.7 km/h
C35 km/h
D40 km/h
Show Answer & Explanation

Correct Answer: B — 32.7 km/h

Time = 2+1+2/3 = 11/3 hrs. Distance = 120 km. Avg = 120×3/11 = 32.7 km/h.

Q20.
Average of 5 numbers is 4.4. Average of 3 of them is 3.2. Average of remaining 2 is:
A5.5
B5.8
C6.0
D6.2
Show Answer & Explanation

Correct Answer: C — 6.0

Sum of 5 = 22. Sum of 3 = 9.6. Sum of 2 = 12.4. Average = 6.2.

More Quantitative Aptitude Topics

Number System Percentages Profit & Loss Ratio & Proportion

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