Question and Answers Forum

All Questions      Topic List

Others Questions

Previous in All Question      Next in All Question      

Previous in Others      Next in Others      

Question Number 94820 by jdmath last updated on 21/May/20

A train which travels at a uniform speed due to mechanical fault after   traveling for an hour goes at 3/5 th of the original speed and reaches the   destination 2 hours late. If the fault occured after traveling another 50  miles the train would have reached 40 minutes earlier. What is the   distance between the two stations ?

$${A}\:{train}\:{which}\:{travels}\:{at}\:{a}\:{uniform}\:{speed}\:{due}\:{to}\:{mechanical}\:{fault}\:{after}\: \\ $$$${traveling}\:{for}\:{an}\:{hour}\:{goes}\:{at}\:\mathrm{3}/\mathrm{5}\:{th}\:{of}\:{the}\:{original}\:{speed}\:{and}\:{reaches}\:{the}\: \\ $$$${destination}\:\mathrm{2}\:{hours}\:{late}.\:{If}\:{the}\:{fault}\:{occured}\:{after}\:{traveling}\:{another}\:\mathrm{50} \\ $$$${miles}\:{the}\:{train}\:{would}\:{have}\:{reached}\:\mathrm{40}\:{minutes}\:{earlier}.\:{What}\:{is}\:{the}\: \\ $$$${distance}\:{between}\:{the}\:{two}\:{stations}\:? \\ $$

Answered by prakash jain last updated on 21/May/20

Assume distance=s km  speed=v (km/hr)  expected time=(s/v)=t  (I)  case when fault occured after 1 hour.  distace traveled in 1 hour=v  remaining distancd=s−v  time taken to cover remaining =((s−v)/((3/5)v))  total time=1+((5(s−v))/(3v))=t+2=(s/v)+2  given that train is late by 2 hrs wrt (I)  1+((5(s−v))/(3v))=t+2=(s/v)+2  (II)  case when fault occured after   after addition 50 kms  distace traveled in 1 hour=v  time taken to cover extra 50 km=((50)/v)  remaining distancd=s−v−50  time taken to cover remaining =((s−v−50)/((3/5)v))  total time=1+((50)/v)+((5(s−v−50))/(3v))  given that train is late by 40 min wrt (I)  40 minutez=(2/3)hrs  1+((50)/v)+((5(s−v−50))/(3v))=t+(2/3)=(s/v)+(2/3)  (III)  solve (I1) & (III) to calculate  required value.

$$\mathrm{Assume}\:\mathrm{distance}=\mathrm{s}\:\mathrm{km} \\ $$$$\mathrm{speed}=\mathrm{v}\:\left(\mathrm{km}/\mathrm{hr}\right) \\ $$$$\mathrm{expected}\:\mathrm{time}=\frac{\mathrm{s}}{\mathrm{v}}=\mathrm{t}\:\:\left(\mathrm{I}\right) \\ $$$$\boldsymbol{\mathrm{case}}\:\boldsymbol{\mathrm{when}}\:\boldsymbol{\mathrm{fault}}\:\boldsymbol{\mathrm{occured}}\:\boldsymbol{\mathrm{after}}\:\mathrm{1}\:\boldsymbol{\mathrm{hour}}. \\ $$$$\mathrm{distace}\:\mathrm{traveled}\:\mathrm{in}\:\mathrm{1}\:\mathrm{hour}=\mathrm{v} \\ $$$$\mathrm{remaining}\:\mathrm{distancd}=\mathrm{s}−\mathrm{v} \\ $$$$\mathrm{time}\:\mathrm{taken}\:\mathrm{to}\:\mathrm{cover}\:\mathrm{remaining}\:=\frac{\mathrm{s}−\mathrm{v}}{\frac{\mathrm{3}}{\mathrm{5}}\mathrm{v}} \\ $$$$\mathrm{total}\:\mathrm{time}=\mathrm{1}+\frac{\mathrm{5}\left(\mathrm{s}−\mathrm{v}\right)}{\mathrm{3v}}=\mathrm{t}+\mathrm{2}=\frac{\mathrm{s}}{\mathrm{v}}+\mathrm{2} \\ $$$$\mathrm{given}\:\mathrm{that}\:\mathrm{train}\:\mathrm{is}\:\mathrm{late}\:\mathrm{by}\:\mathrm{2}\:\mathrm{hrs}\:\mathrm{wrt}\:\left(\mathrm{I}\right) \\ $$$$\mathrm{1}+\frac{\mathrm{5}\left(\mathrm{s}−\mathrm{v}\right)}{\mathrm{3v}}=\mathrm{t}+\mathrm{2}=\frac{\mathrm{s}}{\mathrm{v}}+\mathrm{2}\:\:\left(\mathrm{II}\right) \\ $$$$\boldsymbol{\mathrm{case}}\:\boldsymbol{\mathrm{when}}\:\boldsymbol{\mathrm{fault}}\:\boldsymbol{\mathrm{occured}}\:\boldsymbol{\mathrm{after}}\: \\ $$$$\boldsymbol{\mathrm{after}}\:\boldsymbol{\mathrm{addition}}\:\mathrm{50}\:\boldsymbol{\mathrm{kms}} \\ $$$$\mathrm{distace}\:\mathrm{traveled}\:\mathrm{in}\:\mathrm{1}\:\mathrm{hour}=\mathrm{v} \\ $$$$\mathrm{time}\:\mathrm{taken}\:\mathrm{to}\:\mathrm{cover}\:\mathrm{extra}\:\mathrm{50}\:\mathrm{km}=\frac{\mathrm{50}}{\mathrm{v}} \\ $$$$\mathrm{remaining}\:\mathrm{distancd}=\mathrm{s}−\mathrm{v}−\mathrm{50} \\ $$$$\mathrm{time}\:\mathrm{taken}\:\mathrm{to}\:\mathrm{cover}\:\mathrm{remaining}\:=\frac{\mathrm{s}−\mathrm{v}−\mathrm{50}}{\frac{\mathrm{3}}{\mathrm{5}}\mathrm{v}} \\ $$$$\mathrm{total}\:\mathrm{time}=\mathrm{1}+\frac{\mathrm{50}}{\mathrm{v}}+\frac{\mathrm{5}\left(\mathrm{s}−\mathrm{v}−\mathrm{50}\right)}{\mathrm{3v}} \\ $$$$\mathrm{given}\:\mathrm{that}\:\mathrm{train}\:\mathrm{is}\:\mathrm{late}\:\mathrm{by}\:\mathrm{40}\:\mathrm{min}\:\mathrm{wrt}\:\left(\mathrm{I}\right) \\ $$$$\mathrm{40}\:\mathrm{minutez}=\frac{\mathrm{2}}{\mathrm{3}}\mathrm{hrs} \\ $$$$\mathrm{1}+\frac{\mathrm{50}}{\mathrm{v}}+\frac{\mathrm{5}\left(\mathrm{s}−\mathrm{v}−\mathrm{50}\right)}{\mathrm{3v}}=\mathrm{t}+\frac{\mathrm{2}}{\mathrm{3}}=\frac{\mathrm{s}}{\mathrm{v}}+\frac{\mathrm{2}}{\mathrm{3}}\:\:\left(\mathrm{III}\right) \\ $$$$\mathrm{solve}\:\left(\mathrm{I1}\right)\:\&\:\left(\mathrm{III}\right)\:\mathrm{to}\:\mathrm{calculate} \\ $$$$\mathrm{required}\:\mathrm{value}. \\ $$

Commented by necxxx last updated on 21/May/20

mr. Prakash Jain welcome back. I  sincerely miss you on this forum.

$${mr}.\:{Prakash}\:{Jain}\:{welcome}\:{back}.\:{I} \\ $$$${sincerely}\:{miss}\:{you}\:{on}\:{this}\:{forum}. \\ $$

Commented by jdmath last updated on 21/May/20

thanks rly sir

$${thanks}\:{rly}\:{sir} \\ $$

Terms of Service

Privacy Policy

Contact: info@tinkutara.com