pt usha and shelly john decide to run a marathan between ramnagar and jamnagar. both start from ramnagar at 1 pm.on the way are two towns:ramgarh and rampur seprated by a distance of 15 km .pt usha reaches ramgarh in 90 minutes running at a constant speed of 40 km/hr.she takes additional 30 minutes to reach rampur.between rampur and jamnagar she maintains at average speed of v km/hr.shelly john being a professional marathan runner,maintains a constant speed of 18 km/hr.they both reach jamnagar togethar after n hours.what could be the total time taken by pt usha.

a:5 hours
b:15 hours
c:41 hours
d:all of the aboce.

• i think all of above.i am adding some facts along with above answer.
  when we will put n=5,that is 75-2v/18-v=5 then v will be =5 km/hr.
  and when we will put n=15 ,that is 75-2v/18-v=15.then v will be 15 km/hr.and then we will put 75-2v/18-v=41.then v will be 17km/hr.so 5 ,15,17 all the values of v are satisfying the equation .so answer will be all of the above.
• 12 years agoHelpfull: Yes(33) No(3)
• answer 5 hours
  
  ramnagar-------60km------ramgrah-------15km-----rampur----(n-2)vkm----jamnagar
  
  total distance covered by shelly =18n
  total distance covered by usha =60+15+(n-2)v=75+nv-2v
  
  18n =75+nv-2v
  
  18n-nv= 75-2v
  
  n(18-v) =75-2v
  
  n =75-2v/18-v
  
  as n being a natural number the only satisfying above equation is when v =5
  
  then n=65/13 =5
  
• 12 years agoHelpfull: Yes(29) No(11)
• JOMON V J
  
  v | n
  -------
  5 | 5
  13| 15
  17| 17
  
  all of the above
• 12 years agoHelpfull: Yes(12) No(0)
• thank you ankur for giving the correction to my answer.
• 12 years agoHelpfull: Yes(8) No(4)
• but y n-2 ???? jomon sir
  
• 11 years agoHelpfull: Yes(6) No(0)
• BC ques to sahi post karo
  Distance between ramgarh and rampur is 15 km. PT usha takes 30 min to reach rampur from ramgarh at speed of 40 km/hr how is it possible MFu**er
  
• 9 years agoHelpfull: Yes(1) No(4)
• Here (n-2) is done because Usha has spent 90 mins+ 30 mins in running=9+30=120 mins i.e. 2 hours.
  So total time taken to travel from ramgarh to ramnagar=(n-2) hours.
• 7 years agoHelpfull: Yes(1) No(0)
• will anyone describe why (n-2)?
  
• 8 years agoHelpfull: Yes(0) No(0)