premsagar

 Profile Answers by premsagar 

• Oct 4th, 2005

 

answer is wrong. even he walks at 30km/hr for 3 hours we will cover 90km.

arati_nayak2000

 Profile Answers by arati_nayak2000 Questions by arati_nayak2000

• Jan 7th, 2006

 

52.5 km

Poornima

• Mar 31st, 2006

 

hi

  Could u plz tell me how u got the distance as 52.5km.

Ravindra

• Apr 10th, 2006

 

average speed (40+30)/2=35;

so the total distance x+y=35*(3/2)=52.5

harry

• May 11th, 2006

 

Ans:105kmread the question carefully...he starts his return journey at 9:00pm..so one way journey time is 3hrsso the eqn becomesavg spd =35kmph(x+y)/35=3=>x+y=35*3 =105...

keerthi

• Sep 18th, 2007

 

I did not understand why you are saying his one way is 3hrs
I could solve in this way
t1 = time taken on level road. t2 = uphill. t3 = down hill;
the distance traveled uphill and down hill same so
t2*30 = 30*t3; => t2 = t3;---> (1)
total time = 2*t1 + t2 + t3 = 3 hours ---> (2)
2t1+2t3 = 3 -->(3)
total distance = 2*(40t1) + 30*t2+30*t3 ---> (4)
substitute (1) in (4)
80t1 + 60t3 => 40(2t1+3t3) then from (3)
here 2t1=3-2t3 --->(3)
so,
40(3-2t3+3t3)
40(3+t3)
But here I am not able to solve
Can you help me

kat

• Nov 4th, 2007

 

avg speed should be calculated by (x*y)/(x+Y)= (40*30)/70=17.14
therefore 17.14 * 3 =

sravan_reddy001

 Profile Answers by sravan_reddy001 

• Jun 25th, 2008

 

x -> distance on ground
y -> distance on slope

speed on upslope and downslope is same(given) = 30
speed on level ground is 40(given)

time taken  : 2(x/40+y/30) = 3

==> 4x+3y = 180
by trial and error --> x=30, y=20

2(x+y) -> 100 kms

Reshu.v

 Profile Answers by Reshu.v 

• Jul 3rd, 2009

 

Total distance=100km.
While going starting speed is 40km/hr, he walks for 60min i.e. distance=40km
While climbing speed is 30km/hr, he walks for 20min i.e. distance=10km
While cumin back speed is 30km/hr, he walks for 100min i.e. distance=50km
Total time = 60+20+100=180min=3hrs(given)
Total speed=40+10+50=100km.

SenRiki

 Profile Answers by SenRiki 

• Jan 13th, 2010

 

Let the slope distance be y and level groung distance be x.

for downhill: time taken=x/40 + y/30.
for uphill: time taken=(x+y)/30........as there is mentioned the keyword "SAME SPEED".

So, the total distance=x/40+y/30+(x+y)/30=3hrs
=>x/4+y/3+(x+y)/3=30
=>7x+8y=360
=>by trial and error:: y=3, x=48.
so the total one way distance is x+y=52......correct me if my approach is wrong.

guhakoushik

 Profile Answers by guhakoushik 

• Dec 21st, 2010

 

Let the slope distance be y and level ground distance be x.

for downhill: time taken=x/40 + y/30.......(1)
for uphill:     time taken=(x+y)/30........(2)

So the total distance from (1) & (2) we get = x/40 + y/30 + (x+y)/30 = 3hrs
=>x/4 + y/3 + (x+y)/3 = 30
=>7x+8y = 360
=>by trial and error:: x=40 y=10.
so the total one way distance is x+y=50......

then 2(x+y) = 50 x 2 = 100. Ans.