Harikumar

• Sep 12th, 2006

 

the exact time is 11 am

then 30miles/ph reach it on 10am

20 miles/ph reach it on 12am

if they start walking in 6am

then 30m/ph-(10am-6am)  4h*30=120miles

20m/ph-(12am-6am)  6h*20=120miles

ans=120miles

kusuma_b

 Profile Answers by kusuma_b Questions by kusuma_b

• Sep 12th, 2006

 

thanq hari kumar . but he also asked the speed.

shashang

• Sep 13th, 2006

 

Let the time taken to travel with 30 miles/hr be x(1hour early)

Then time taken to travel by 20 miles/hr = x+2(1hour late)

Since the distance traveled with both the speed are same

30 * x = 20 * (x+2) i.e 30 * x = 20 * x + 40

10 * x = 40 i.e x = 4(this is the time taken to travel with 30 miles/hr speed)

Now we know the time taken

Then Distance = speed * time taken i.e 30 * 4 = 120 miles.

To determine speed by which the person has to travel to reach the destination at 11.00 A.M simply divide the distance(found out) by time taken.Here time taken is either one more than time taken for 30 mile/hr travel or one less than

20 miles/hr travel . time taken = 5 hrs (4+1 or 6-2)

speed =  distance/time taken i.e 120/5 = 25 mile/hour.(solution)

Debarghya

• Sep 13th, 2006

 

Let the distance be X miles.

So from the above statements we have.

T1= X/20; also T2= X/30;

Now according to the conditions we can form an equation :

  (X-20)/20 = (X+30)/30;

  Ans X= 120 miles.

Thius time taken in 20 miles/hr = 4 hrs and  6 hrs for 30 miles/hr.

Thus in order to reach in time he should complete it in 5 hrs,so his speed should be  Ans:120/5 = 24 miles/hr. 

kuj vi keh lo!!!

• Nov 29th, 2006

 

let x be the distance between two pointst1=x/20t2=x/30t1-t2=2hrs=> x/20-x/30=2=> x=120Thus t1= 6 hrs t2= 4 hrs.Thus in order to reach in time he should complete it in 5 hrs,so his speed should be Ans:120/5 = 24 miles/hr.

Ahamika

• Jan 7th, 2017

 

shashang, there is a bit of correction. 120/5=24 but you have mentioned it as 25 ( last line )

Aman Arora

• Sep 3rd, 2017

 

120/5 is 24 not 20