ExamVeda
Login
Home

Average - Aptitude MCQ Questions and Solutions with Explanations

Average MCQ Questions and answers with easy and logical explanations.Arithmetic Ability provides you all type of quantitative and competitive aptitude mcq questions on Average with easy and logical explanations. Average MCQ is important for exams like Banking exams,IBPS,SCC,CAT,XAT,MAT etc. Page-10 section-4

Each section contains 100 MCQs on Average .
91
If the mean of 4 observations is 20, when a constant 'c' is added to each observation, the mean becomes 22. The value of c is :
Discuss
Answer & Solution
Answer: Option C
Solution:
Let the four observations are = a, b, d, e
According to the question,
$$\frac{a + b + e + d}{4}$$   = 20.....(i)
$$\frac{a + c + b + c + e + c + d + c}{4}$$     = 22
$$\frac{4c + (a + b + e + d)}{4}$$     = 22
$$\frac{4c}{4}$$ + 20 = 22
c = 2
92
The average age of 30 students is 9 years. If the age of their teacher is included, the average age becomes 10 years. The age of the teacher (in years) is :
Discuss
Answer & Solution
Answer: Option D
Solution:
Let the age of teacher = x years
According to the question,
30 × 9 + x = 31 × 10
270 + x = 310
x = 40 years
93
The average age of 20 boys in a class is 12 years. 5 new boys are admitted to the class whose average age is 7 years. The average age of all the boys in the class becomes:
Discuss
Answer & Solution
Answer: Option D
Solution:
According to the question,
Average
= $$\frac{20 × 12 + 5 × 7}{25}$$
= $$\frac{240 + 35}{25}$$
= $$\frac{275}{25}$$
= 11 years
94
The frequency distribution data is given below. If the average age is 17 years, the value of m is
Age (in years) : 8 20 26 29
No. of people : 3 2 m 1
Discuss
Answer & Solution
Answer: Option A
Solution:
According to the question,
Age (in year) : 8 20 26 29  
No. of people : ↓×3 +↓×2 +↓×m +↓×1 = 6 + m
Total : 24 +40 +26m +29 = 93 + 26m
Average = $$\frac{93 + 26m}{6 + m}$$   = 17
⇒ 93 + 26m = 102 + 17m
⇒ 9m = 9
⇒ m = 1
95
The average of six numbers is 3.95. The average of two of them is 3.4, while the average of the other two is 3.85. The average of the remaining two numbers is :
Discuss
Answer & Solution
Answer: Option A
Solution:
Let the six number be a, b, c, d, e, f
According to the question,
⇒ $$\frac{a + b + c + d + e + f}{6}$$     = 3.95
⇒ a + b + c + d + e + f = 23.7.....(i)
$$\frac{a + b}{2}$$  = 3.4
⇒ a + b = 6.8.....(ii)
$$\frac{c + d}{2}$$  = 3.85
⇒ c + d = 7.7.....(iii)
Put the value of equation (ii) and equation (iii) in equation (i)
e + f = 23.7 - 7.7 - 6.8
e + f = 9.2
∴ Average =$$\frac{9.2}{2}$$ = 4.6
96
If the arithmetic mean of 7, 5, 13, x and 9 is 10, then the value of x is :
Discuss
Answer & Solution
Answer: Option D
Solution:
Arithmetic mean
$$\frac{{{\text{Total sum}}}}{{{\text{Total number}}}}$$
According to the question,
⇒ 10 = $$\frac{7 + 5 + 13 + x + 9}{5}$$
⇒ 50 = x + 34
⇒ x = 50 - 34
⇒ x = 16
97
3 years age, the average age of a family of 5 members was 17 years. A baby having been born, the average age of the family is same today. The present age of the baby is :
Discuss
Answer & Solution
Answer: Option C
Solution:
According to the question,
Average age of a family of 5 members 3 years ago
= 17 years sum of ages of a family members
= 5 × 17
= 85 years
A baby having been born the average age of the family is same today.
∴ Sum of age of a family of 6 members
= 17 × 6
= 102 years
∴ Sum of age of a family of 5 members at present
= 85 + 5 × 3
= 85 + 15
= 100 years
∴ Age of child
= 102 - 100 = 2 years
98
If the average of 5 consecutive integers is x then, find the average of next to next 5 consecutive integers.
Discuss
Answer & Solution
Answer: Option C
Solution:
Let number be a, a + 1, a + 2, a + 3, a + 4
Next, a + 5, a + 6, a + 7, a + 8, a + 9
Next to next - a + 10, a + 11, a + 12, a + 13, a + 14
1st condition = $$\frac{5a + 10}{5}$$   = x
5a + 10 = 5x.....(i)
2nd condition
= $$\frac{a + 10 + a + 11 + a + 12 + a + 13 + a + 14}{5}$$
= $$\frac{5a + 50 + 10}{5}$$
From equation (i),
= $$\frac{5x + 50}{5}$$
= x + 10
99
The average age of P, Q and R is 15 years more than R's age. If the total age of P and Q together is 39 years, then R's age is ?
Discuss
Answer & Solution
Answer: Option A
Solution:
$$\frac{P + Q + R}{3}$$   = R + 5
P + Q + R = 3R + 15
P + Q - 2R = 15 . . . . . (i)
P + Q= 39 . . . . . (ii)
From equation (i) and (ii)
39 - 2R = 15
2R = 24
R = 12 years
100
Find the average of 1.11, 0.01, 0.101, 0.001, 0.11 = ?
Discuss
Answer & Solution
Answer: Option A
Solution:
According to the question,
Average
= $$\frac{1.11 + 0.01 + 0.101 + 0.001 + 0.11 }{5}$$
= $$\frac{1.332}{5}$$
= 0.2664