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Time Distance and Speed
If a man walks a certain distance in 20 days when he rests 10 h each day, how long, will it take him to walk three times as far, if he walks twice as fast and rest 12 h each day?
Read Solution (Total 2)
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- case1-
days=20
rest per day=10hr
walks per day=24-10=14hr
time for 20 days=14*20=280hr
d=s*t
d/s=t
d/s=280 -> 1st equation
case2-
D=3d where D=new distance and d=old distance
S=2s where S=new speed and s=old speed
D=S*T where T=new time
put the values of D and S
3d=2s *T
3d/2s=T
put the value of d/s from 1st equation
3/2 * 280 =T
T=420 hr
rest per day=12 hr
walks per day=24-12=12hr
he is walking 12hrs per day so , he requires 35 days for 420 hrs. - 10 years agoHelpfull: Yes(4) No(0)
- case 1 : when he rests 10 hrs each day , that means he walks for 14hrs each day .
that means he walks for 280 hours in total.
now let the total distance be X. then speed will be x/280.
case2: when he walks 3 times more , then the total distance becomes 3x. also he walks twice as fast , therfore speed in this case will be x/140.
now the total time taken to cover this distance will be 3x (140/x)= 420 hrs.
now when he rest for 12 hrs each day , that means he travels for 12 hrs each day.
therefore total days taken = 420/12=35 - 8 years agoHelpfull: Yes(0) No(0)
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