Average Aptitude Questions and Answers:

Overview:

Questions and Answers Type:	MCQ (Multiple Choice Questions).
Main Topic:	Quantitative Aptitude.
Quantitative Aptitude Sub-topic:	Average Aptitude Questions and Answers.
Number of Questions:	10 Questions with Solutions.

1. What will be the average of $15, 20, 25, 30 \ ?$

$24.2$
$22.2$
$22.5$
$23.5$

Answer: (c) $22.5$

Solution: Given values, $15, 20, 25, 30$ then according to average formula- $$ Average = \frac{k_1 + k_2 + k_3 + k_4}{4} $$ $$ = \frac{15 + 20 + 25 + 30}{4} = \frac{90}{4} = 22.5 $$

2. If the distance between two stations $x$ and $y$ is $100 \ km$. A train covers the distance from $x$ to $y$ at the speed of $50 \ km/hr$ and returns from $y$ to $x$ at the speed of $100 \ km/hr$. Find the average speed of the train during the whole journey?

$70.05 \ km/hr$
$60 \ km/hr$
$65.67 \ km/hr$
$66.67 \ km/hr$

Answer: (d) $66.67 \ km/hr$

Solution: Given values, $x_1 = 50 \ km/hr$, and $x_2 = 100 \ km/hr$ then $$ Average \ speed = \frac{2 \ x_1 \ x_2}{x_1 + x_2} $$ $$ = \frac{2 \times 50 \times 100}{50 + 100} = \frac{10000}{150} = 66.67 \ km/hr $$

3. If the distance between two cities is $150 \ km$. A man travels from one city to another in $60 \ minutes$ and returns in $80 \ minutes$. Find average speed of the man?

$3.23 \ km/hr$
$2.1429 \ km/hr$
$2 \ km/hr$
$3.1429 \ km/hr$

Answer: (b) $2.1429 \ km/hr$

Solution: Given values, $d_1 = d_2 = 150 \ km$, $t_1 = 60 \ minutes$, and $t_2 = 80 \ minutes$ then $$ Average \ speed = \frac{d_1 + d_2}{t_1 + t_2} $$ $$ = \frac{150 + 150}{80 + 60} = \frac{300}{140} = 2.1429 \ km/min $$

4. What will be the average of $100, 150, 250 \ ?$

$170$
$166.67$
$165.67$
$155.58$

Answer: (b) $166.67$

Solution: $$ Average = \frac{k_1 + k_2 + k_3}{3}$$ $$ = \frac{100 + 150 + 250}{3} $$ $$ = \frac{500}{3} = 166.67 $$

5. Find the average of the numbers between $20$ to $60$, which divisible by $5 \ ?$

$50$
$42$
$40$
$35$

Answer: (c) $40$

Solution: First number divisible by $5$ after $20$ is $25$ and last number divisible by $5$ before $60$ is $55$, then $$ Average = \frac{25 + 55}{2} = \frac{80}{2} = 40 $$

6. A student obtained $50$ marks in Mathematics, $60$ marks in English, $70$ marks in Hindi, and $80$ marks in Sports. Find out the average marks obtained by student?

$65$
$67$
$70$
$68$

Answer: (a) $65$

Solution: Average marks obtained by the student $$ Average = \frac{k_1 + k_2 + k_3 + k_4}{4} $$ $$ = \frac{50 + 60 + 70 + 80}{4} = \frac{260}{4} = 65 \ marks $$

7. The average of seven numbers is $50$, if one number is excluded then average becomes $55$. Find out the excluded number?

$20$
$26$
$25$
$28$

Answer: (a) $20$

Solution: Seven numbers average is $50$ and after one number excluded then six numbers average is $55$ then $$Average \ increases = 55 - 50 = 5 $$ $$ Total \ increased \ number = 5 \times 6 = 30 $$ it means excluded number is $30$ less than average of seven numbers $50$ $$ then \ excluded \ number = 50 - 30 = 20 $$

8. Find the average of the numbers between $40$ to $80$, which divisible by $3 \ ?$

$44$
$55$
$60$
$58$

Answer: (c) $60$

Solution: First number divisible by $3$ after $40$ is $42$ and last number divisible by $3$ before $80$ is $78$, then $$ Average = \frac{42 + 78}{2} = \frac{120}{2} = 60 $$

9. If the distance between two stations $M$ and $N$ is $300 \ km$. A train covers the distance from $M$ to $N$ in $4 \ hours$ and returns from $N$ to $M$ in $6 \ hours$ then find out the average speed of the train?

$56 \ km/hr$
$60 \ km/hr$
$65 \ km/hr$
$62 \ km/hr$

Answer: (b) $60 \ km/hr$

Solution: Given values, $d_1 = d_2 = 300 \ km$, $t_1 = 4 \ hours$, and $t_2 = 6 \ hours$ then $$ Average \ speed = \frac{d_1 + d_2}{t_1 + t_2} $$ $$ = \frac{300 + 300}{4 + 6} = \frac{600}{10} = 60 \ km/hr $$

10. A bus covers a certain distance at the speed of $20 \ km/hr$, $50 \ km/hr$ and $70 \ km/hr$. Find out the average speed of the bus?

$50 \ km/hr$
$45.67 \ km/hr$
$46.67 \ km/hr$
$57.67 \ km/hr$

Answer: (c) $46.67 \ km/hr$

Solution: $$Average \ speed = \frac{20 + 50 + 70}{3}$$ $$ = \frac{140}{3} = 46.67 \ km/hr $$