✕

Find the best tutors and institutes for Class 10 Tuition

Find Best Class 10 Tuition

✕

Search for topics

A motor boat whose speed is 18 km/h in still water takes 1 hour more to go 24 km upstream than to return downstream to the same spot. Find the speed of the stream.

Follow 4

4 Answers

Let the speed of stream by x km/h. Speed of boat upstream = ( 18- x ) kmph Speed of boat downstream = ( 18+x ) kmph Now time = Distance / Speed Time taken to go upstream - Time taken to go downstream = 1hr 24/(18-x) - 24/(18+x) = 1 -48x = 324 - x2 x2-48x-324 = 0 x2-54x+6x-324=0 x(x-54)+6(x-54)=0 (x+6)(x-54)=0... read more

Let the speed of stream by x km/h. Speed of boat upstream = ( 18- x ) kmph Speed of boat downstream = ( 18+x ) kmph Now time = Distance / Speed Time taken to go upstream - Time taken to go downstream = 1hr 24/(18-x) - 24/(18+x) = 1 -48x = 324 - x2 x2-48x-324 = 0 x2-54x+6x-324=0 x(x-54)+6(x-54)=0 (x+6)(x-54)=0 therefore x = 54 ( as x cannot be -6) Speed of the stream is 54kmph read less

0

Comments

Let, speed of boat in still water =u km/hr, Speed of stream= v km/hr Speed downstream=u+v, speed upstream=u-v. Speed downstream=18+v, Speed upstream=18-v, 24/t=18+v, 24/t+1=18-v, Adding both equations we get, 24/t+(24/t+1)=36 Solving we get quadratic equation 3t^2-3t-2=0. We get t=1 and t=-2/3. As time... read more

Let, speed of boat in still water =u km/hr,

Speed of stream= v km/hr

Speed downstream=u+v,

speed upstream=u-v.

Speed downstream=18+v,

Speed upstream=18-v, 24/t=18+v, 24/t+1=18-v,

Adding both equations we get,

24/t+(24/t+1)=36

Solving we get quadratic equation 3t^2-3t-2=0.

We get t=1 and t=-2/3.

As time cannot be negative t=1.

Speed downstream=24/1=24.

Speed upstream=24/2=12

speed of stream=(1/2)*Speed downstream-Speed upstream

=(24-12)/2=6 km/hr.

read less 0

Comments

Let the speed of stream by x km/h. Speed of boat upstream = ( 18- x ) kmph Speed of boat downstream = ( 18+x ) kmph Now time = Distance / Speed Time taken to go upstream - Time taken to go downstream = 1hr 24/(18-x) - 24/(18+x) = 1 -48x = 324 - x2 x2-48x-324 = 0 x2-54x+6x-324=0 x(x-54)+6(x-54)=0 (x+6)(x-54)=0 therefore... read more

Let the speed of stream by x km/h. Speed of boat upstream = ( 18- x ) kmph Speed of boat downstream = ( 18+x ) kmph Now time = Distance / Speed Time taken to go upstream - Time taken to go downstream = 1hr 24/(18-x) - 24/(18+x) = 1 -48x = 324 - x2 x2-48x-324 = 0 x2-54x+6x-324=0 x(x-54)+6(x-54)=0 (x+6)(x-54)=0 therefore x = 54 ( as x cannot be -6) Speed of the stream is 54kmph read less

0

Comments

View 2 more Answers

Related Questions

Vishal Ranjan asked How much monthly fees for Maths for class 10 in Delhi or NCR?

Vishal Ranjan asked How much monthly fee for class 10 for 1 subject like Maths in Delhi or NCR?

Now ask question in any of the 1000+ Categories, and get Answers from Tutors and Trainers on UrbanPro.com

Ask a QuestionRecommended Articles

CBSE Hindi Class 10 Syllabus 2018-2019

Like Mathematics and Science, Hindi is also an essential part of the class 10 syllabus, which requires regular and sufficient preparation. Many students might mistake this subject to be an easy one and give less importance. If you want to score good percentage, remember that marks obtained in Hindi will also matter. They...

CBSE Syllabus for Class 10 English Communicative...

CBSE Board Exams are approaching soon, and students are getting more serious with their preparations. Scoring good marks need a lot of preparation and attention. However, if they follow the right strategy then, scoring high marks won t be so tough. One of the main rules that toppers follow during the exam preparation...

CBSE Class 10 Language & Literature Syllabus...

Board exams are an integral part of a student s life. It prepares them for the future and strengthens their observation. Besides, boards exams also teach students valuable traits like time management, punctuality, determination, self-control and perseverance. We at UrbanPro, understand the importance of exams in a student...

CBSE Science Class 10 Syllabus for 2018-2019

Class 10 is the first external exam in a student s life. It decides the admission process in future, as almost all colleges and universities grant a seat based on Class 10th marks, as one of the criteria. For students who plan to opt for science as their stream in higher classes, it is essential that they begin preparation...

Find Class 10 Tuition near you

Looking for Class 10 Tuition ?

Find best Class 10 Tuition in your locality on UrbanPro.

Are you a Tutor or Training Institute?

Join UrbanPro Today to find students near you