Ram covers a part of the journey at 20 kmph and the balance at 70 kmph taking the total of 8 hours to cover the distance of 400 km. how many hours has been driving at 20 kmph? a 2 hours 3 hours 20 minutes c 2 hours 40 minutes 3 hours 12 minutes
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Let the first part of the journey is covered in x hours and balance in y hours
Total distance travelled = 20x + 70y
=> 20x + 70y = 400 ...(1)
Total time = 8 hr
=> x + y = 8 ...(2)
Solving (1) and (2)
(2)×70-(1)=> 50x = 70×8-400
50x = 160
x = 160/50 = 3.2 hour
Required time = 3.2 hours
Total distance travelled = 20x + 70y
=> 20x + 70y = 400 ...(1)
Total time = 8 hr
=> x + y = 8 ...(2)
Solving (1) and (2)
(2)×70-(1)=> 50x = 70×8-400
50x = 160
x = 160/50 = 3.2 hour
Required time = 3.2 hours
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