Answers

  • Brainly User
2014-05-24T18:00:29+05:30
Raja travelled 2/5 of his journey at 50 km/h. The next 1/5 of his journey he travelled at 40 km/h. The remaining 40 km he covered in half an hour. How much time did he take for the whole journey?
Solution:
 Let the Total distance Of Journey = X km 
 Speed for  traveling  ( 2/5 )*X = 50 km /hr
 Speed for traveling (1/5)*X  = 40 km / hr

 Remaining distance = 40 km
We know that  remaining Distance  = X - 2/5*X  - 1/5*X
                                            = X (1-2/5 - 1/5)
                                            = X ( 1 - 3/5 )
                                           = 2/5*X
                 2/5 *X = 40
                 X = 5/2 *40
                 X= 100 km 
Therefore Total Distance Of Journey = 100 KM     
 
hence , The Persons Travels first 40 km of his journey with a speed of 50 Km/ hr , next 20 Km with the speed of 40 Km / hr and the last 40 Km in half an Hour .

Therefore the Total time taken by him to complete journey  = (40 / 50 + 20 /40 + 0.5 )hrs     
NOte :-
       Speed  = distance / time ;
     => time = distance / speed
          That's why I  used 40 / 50 and 20 / 40 in calculating the time taken to travel the first 40 km and 20 km of the journey.     
                                                   = (0.8 + 0.5 + 0 .5 )hrs
                                                  = 1.8 hrs

Hope this is helpful!!
0
2014-05-25T08:50:19+05:30
Raja travelled 2/5 of his journey at 50 km/h. The next 1/5 of his journey he travelled at 40 km/h. The remaining 40 km he covered in half an hour. How much time did he take for the whole journey?
Solution:
 Let the Total distance Of Journey = X km  
 Speed for  traveling  ( 2/5 )*X = 50 km /hr
 Speed for traveling (1/5)*X  = 40 km / hr

 Remaining distance = 40 km 
We know that  remaining Distance  = X - 2/5*X  - 1/5*X
                                            = X (1-2/5 - 1/5)
                                            = X ( 1 - 3/5 )
                                           = 2/5*X
                 2/5 *X = 40 
                 X = 5/2 *40 
                 X= 100 km  
Therefore Total Distance Of Journey = 100 KM      
 
hence , The Persons Travels first 40 km of his journey with a speed of 50 Km/ hr , next 20 Km with the speed of 40 Km / hr and the last 40 Km in half an Hour .

Therefore the Total time taken by him to complete journey  = (40 / 50 + 20 /40 + 0.5 )hrs      
NOte :-
       Speed  = distance / time ;
     => time = distance / speed 
          That's why I  used 40 / 50 and 20 / 40 in calculating the time taken to travel the first 40 km and 20 km of the journey.      
                                                   = (0.8 + 0.5 + 0 .5 )hrs
                                                  = 1.8 hrs 
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