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.

Asked by Last Modified  

Follow 4
Answer

Please enter your answer

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
Comments

Maths Tutor

6kmph
Comments

Conceptual understanding is the key to success.

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
Comments

Maths Tutor

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
Comments

View 2 more Answers

Related Questions

If the radius of the base of a cone is doubled keeping the height same. What is the ratio of the volume of the larger cone to the smaller cone?
When we take height=h and radios of base=r then volume of cone=?r^2*h/3 if radios of the base is doubled then R=2r and height=h so, volume is =?(2r)^2*h/3 therefore, ratio of the volume of latter cone...
Santosh
0 0
5
Find the zeroes of the quadratic polynomial x2 + 5x + 6 and verify the relationship between the zeroes and the coefficients.
Let p(x)= x2+5x+6 Now putting p (x)=0 X2+5x+6=0 X2+3x+2x+6=0 X (x+3)+2 (x+3)=0 (X+3)(x+2)=0 (X+3)=0,(x+2)=0 X=-3,x=-2 Therefor -3 and -2 are zeros of given polynomial p (x)and names alpha and beta Now...
Rekha
0 0
5
Is college algebra hard compared to high school algebra?
Not much,but lots of theorems and equations you need to solve than the high school algebra.
Abhishek
0 0
7

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

Ask a Question

Related Lessons



Real numbers -number system rational and irrational numers
Real numbers -Rational numbers are numbers which are written in the form of p/q where p,q are natural numbers and q is not equal to zero.irrational numbers are numbers which cannot be written in the form...
S

Surface Area of Hemi (Semi) Sphere
If, the radius of a sphere=r Then, 1)CURVED SURFACE AREA OF SEMI(HEMI) SPHERE= 2πr2 2)TOTAL SURFACE AREA OF SEMI(HEMI) SPHERE= 3πr2 Ex;- If,radius of a sphere=r=14cm 1)CURVED SURFACE AREA...

Trigonometric ratios for complementary angles
When the sum of two angles=90 degrees, they are called complementary angles. We can use following formula →sin(90-θ)=cosθ,cos(90-θ)=sinθ,tan(90-θ)=cotθ,cosec(90-θ)=secθ,sec(90-θ)=cosecθ We...

Recommended Articles

Sandhya is a proactive educationalist. She conducts classes for CBSE, PUC, ICSE, I.B. and IGCSE. Having a 6-year experience in teaching, she connects with her students and provides tutoring as per their understanding. She mentors her students personally and strives them to achieve their goals with ease. Being an enthusiastic...

Read full article >

Quest Academy is a professional Bangalore based NEET and JEE (Main + Advanced) training institute. The academy was incorporated in 2015 to cater to the needs of students, who aim to crack competitive exams by connecting with the best brains around. The institute helps students enhance their skills and capabilities through...

Read full article >

Raghunandan is a passionate teacher with a decade of teaching experience. Being a skilled trainer with extensive knowledge, he provides high-quality BTech, Class 10 and Class 12 tuition classes. His methods of teaching with real-time examples makes difficult topics simple to understand. He explains every concept in-detail...

Read full article >

Mohammad Wazid is a certified professional tutor for class 11 students. He has 6 years of teaching experience which he couples with an energetic attitude and a vision of making any subject easy for the students. Over the years he has developed skills with a capability of understanding the requirements of the students. This...

Read full article >

Looking for Class 10 Tuition ?

Learn from the Best Tutors on UrbanPro

Are you a Tutor or Training Institute?

Join UrbanPro Today to find students near you