Question

Nidhi takes 3 hours more than Renu to walk 30 km. But if Nidhi doubles his pace , she is ahead of Renu by 3/2hrs. Find their speed of walking

Answer 1

Let the speed of Nidhi be x km/hr.

Let the speed of Renu be y km/hr.

We know that Time = Distance/Speed.

Time taken by Nidhi = 30/x   ------ (1)

Time taken by Renu = 30/y   ------ (2)

Given that Nidhi takes 3 hours more than Renu to walk 30km.

= > (30/x) - (30/y) = 3

= > (10/x) - (10/y) = 1   --------- (1)

Given that Nidhi doubles his pace. 

Then, Speed of Nidhi will be 2x km/hr.

Time taken by Nidhi will be 30/2x.

Now,

$= \ \textgreater \ \frac{30}{y} - \frac{30}{2x} = \frac{3}{2}$

$= \ \textgreater \ \frac{10}{y} - \frac{5}{x} = \frac{1}{2} ----- (2)$


On solving (1) & (2), we get

Let 1/x = u and 1/y = v.

= > 10u - 10v = 1

= > -5u + 10v = 1/2

      ------------------------

       5u = (3/2)

       10u = 3

          u = 3/10.    -------- (3) 


Then,

10u - 10v = 1

= > 10(3/10) - 10v = 1

= > 3 - 10v = 1

= > -10v = -2

= > v = 1/5.   ------ (4)


From (3), u = (3/10)

 = > (1/x) = (3/10)

= > x = (10/3).



From (4), v = (1/5)

= > (1/y) = (1/5)

= > y = 5.



Therefore, Speed of Nidhi = 10/3 km/hr

                   Speed of Renu = 5km/hr.




Hope this helps!

Answer 2

bro according to my calculation Nithi speed is 10/3 km/h and renu speed is 5km/h

Bro / Anna / bhaee ( usually I dont know hindi I learn it from google) please mark my answer as brainlist please