Model 3 Problems on average speed Section-Wise Topic Notes With Detailed Explanation And Example Questions
MOST IMPORTANT quantitative aptitude - 5 EXERCISES
The following question based on time & distance topic of quantitative aptitude
(a) 4 km/hour more
(b) 5 km/hour less
(c) 3 km/hour more
(d) 3 km/hour less
The correct answers to the above question in:
Answer: (c)
Using Rule 2,If a man travels different distances $d_1,d_2,d_3$,... and so on in different time $t_1,t_2,t_3$ respectively then,Average speed= $\text"total travelled distance"/\text"total time taken in travelling distance"$= ${d_1 + d_2 + d_3 +...}/{t_1 + t_2 + t_3 +...}$
Remaining distance
= (3584 - 1440 - 1608) km
= 536 km.
This distance is covered at the rate of $536/8$ = 67 kmph.
Average speed of whole journey
= $3584/56$ = 64 kmph
Required difference in speed
= (67 - 64) kmph i.e. = 3 kmph more
Discuss Form
Read more problems on average speed Based Quantitative Aptitude Questions and Answers
Question : 1
A man walks from his house at an average speed of 5 km per hour and reaches his office 6 minutes late. If he walks at an average speed of 6 km/h he reaches 2 minutes early. The distance of the office from his house is
a) 12 km
b) 4 km
c) 6 km
d) 9 km
Answer »Answer: (b)
Required distance of office from house = x km. (let)
Time = $\text"Distance"/ \text"Speed"$
According to the question,
$x/5 - x/6 = {6 + 2}/60 = 2/15$
${6x - 5x}/30 = 2/15$
$x/30 = 2/15$
$x = 2/15$ × 30 = 4 km.
Using Rule 10,If a man travels at the speed of $s_1$, he reaches his destination $t_1$ late while he reaches $t_2$ before when he travels at $s_2$ speed, then the distance between the two places is D = ${(S_1 × S_2)(t_1 + t_2)}/{S_2 - S_1}$
Here, $S_1 = 5, t_1 = 6, S_2 = 6, t_2$ = 2
Distance = ${(S_1 × S_2)(t_1 + t_2)}/{S_2 - S_1}$
= ${(5 × 6)(6 + 2)}/{6 - 5}$
= $30 × 8/60$ = 4 km.
Question : 2
One third of a certain journey is covered at the rate of 25 km/ hour, one-fourth at the rate of 30 km/hour and the rest at 50 km/ hour. The average speed for the whole journey is
a) 30 km/hour
b) 37$1/12$ km/hour
c) 35 km/hour
d) 33$1/3$ km/hour
Answer »Answer: (d)
Let the total distance be x km.
Total time = ${x/3}/25 + {x/4}/30 +{{5x}/12}/50$
= $x/75 + x/120 + x/120$
= $x/75 + x/60 = {4x + 5x}/300 = {3x}/100$ hours
Average speed
= $\text"Total distance"/\text"Time taken"$
= $x/{{3x}/100} = 100/3 = 33{1}/3$ kmph
Using Rule 18,If a man covers $1/x$ part of Journey at u km/h,$1/y$ part at v km/h and $1/z$ part at w km/hr and so on, then his average speed for the whole journey will be $1/{1/{xu} + 1/{yv} + 1/{zw} +...}$
Here, x = 3, u = 25
y = 4, v = 30
z = $12/5$ , w = 50
Average Speed= $1/{1/{xu} + 1/{yv} + 1/{zw}}$
= $1/{1/{3 × 25} + 1/{4 × 30} + 1/{12/5 × 50}}$
= $1/{1/75 + 1/120 + 1/120}$
= $1/{1/75 + 1/60} = 1/{{4 + 5}/300}$
= $300/9 = 100/3$
= 33$1/3$ km/hr.
Question : 3
At an average of 80 km/hr Shatabdi Express reaches Ranchi from Kolkata in 7 hrs. The distance between Kolkata and Ranchi is
a) 560 m.
b) 650 m.
c) 560 km.
d) 506 km.
Answer »Answer: (c)
Distance = Speed × Time
= (80 × 7) km. = 560 km.
Question : 4
The speed of a train going from Nagpur to Allahabad is 100 kmph while its speed is 150 kmph when coming back from Allahabad to Nagpur. Then the average speed during the whole journey is :
a) 140 kmph
b) 135 kmph
c) 120 kmph
d) 125 kmph
Answer »Answer: (c)
Using Rule 5,
Here, the distances are equal.
Average speed
= $({2 × 100 × 150}/{100 + 150})$ kmph
= ${2 × 100 × 150}/250$ = 120 kmph
Question : 5
P travels for 6 hours at the rate of 5 km/ hour and for 3 hours at the rate of 6 km/ hour. The average speed of the journey in km/ hour is
a) 1$2/9$
b) 2$2/5$
c) 3$1/5$
d) 5$1/3$
Answer »Answer: (d)
Using Rule 2,If a man travels different distances $d_1,d_2,d_3$,... and so on in different time $t_1,t_2,t_3$ respectively then,Average speed= $\text"total travelled distance"/\text"total time taken in travelling distance"$= ${d_1 + d_2 + d_3 +...}/{t_1 + t_2 + t_3 +...}$
Total distance
= 5 × 6 + 3 × 6
= 30 + 18 = 48 km
Total time = 9 hours
Average speed
= $48/9 = 16/3 = 5{1}/3$ kmph
Question : 6
On a journey across Kolkata, a taxi averages 50 km per hour for 50% of the distance, 40 km per hour for 40% of it and 20 km per hour for the remaining. The average speed (in km/hour) for the whole journey is :
a) 35
b) 45
c) 42
d) 40
Answer »Answer: (d)
Using Rule 2,
Total distance = 100 km.
Total time = $50/50 + 40/40 + 10/20$
= $1 + 1 + 1/2 = 5/2$ hours
Average speed = ${100 × 2}/5$ = 40 kmph
GET time & distance PRACTICE TEST EXERCISES
Model 1 Basic Time & Distance using formula
Model 2 Vehicles in x/y of its usual speed
Model 3 Problems on average speed
Model 4 Time & Distance with Ratios
Model 5 Problems with Races
time & distance Shortcuts and Techniques with Examples
-
Model 1 Basic Time & Distance using formula
Defination & Shortcuts … -
Model 2 Vehicles in x/y of its usual speed
Defination & Shortcuts … -
Model 3 Problems on average speed
Defination & Shortcuts … -
Model 4 Time & Distance with Ratios
Defination & Shortcuts … -
Model 5 Problems with Races
Defination & Shortcuts …
Verbal Reasoning
Question & Answer Quiz
Non Verbal Reasoning
Question & Answer Quiz
Quantitative Aptitude
Question & Answer Quiz
Computer MCQ
Question & Answer Quiz
General English
Question & Answer Quiz
History GK
Question & Answer Quiz
Polity GK
Question & Answer Quiz
Geography GK
Question & Answer Quiz
Economy GK
Question & Answer Quiz
General Awareness GK
Question & Answer Quiz
Recently Added Subject & Categories For All Competitive Exams
100+ Quadratic Equation Questions Answers PDF for Bank
Quadratic Equation multiple choice questions with detailed answers for IBPS RRB SO. more than 250 Attitude practice test exercises for all competitive exams
Continue Reading »
IBPS Aptitude Linear Equations MCQ Questions Answers PDF
Linear equations multiple choice questions with detailed answers for IBPS RRB SO. more than 250 Attitude practice test exercises for all competitive exams
Continue Reading »
New 100+ Compound Interest MCQ with Answers PDF for IBPS
Compound Interest verbal ability questions and answers solutions with PDF for IBPS RRB PO. Aptitude Objective MCQ Practice Exercises all competitive exams
Continue Reading »
100+ Mixture and Alligation MCQ Questions PDF for IBPS
Most importantly Mixture and Alligation multiple choice questions and answers with PDF for IBPS RRB PO. Aptitude MCQ Practice Exercises all Bank Exams
Continue Reading »