Question

Deepak walks around a rectangular Park of length 115 metre and the width 85 metre at 4 kilometre per hour in how much time will he complete 5 rounds​

Answer 1

Perimeter of the park is = 2(115+85)m = 400m
For 5 round Deepak will travel 5*400= 2000m= 2km
He can complete 4km per hour.
4km can complete in 1 hr
1km can complete in 1/4 hr
2km can complete in 2*1/4 hr= 2/4 hr= 1/2hr= 30min
Therefore, he completes 5 round in 30min.

Answer 2

Given data : Deepak walks around a rectangular Park of length 115 metre and the width 85 metre at 4 kilometre per hour.

To find : Time taken by Deepak to complete 5 round ?

Solution : According to given data :

⟹ Length = 115 metre

⟹ Breadth = 85 metre

⟹ Speed = 4 km/hr

Now,

⟹ 4 km/hr = 4000/3600 m/s

⟹ 4 km/hr = 10/9 m/s

Hence,

⟹ Speed = 10/9 m/s

Now,

⟹ Perimeter of rectangular park

= 2 ( length + breadth )

⟹ Perimeter of rectangular park

= 2 ( 115 + 85 )

⟹ Perimeter of rectangular park

= 2 ( 200 )

⟹ Perimeter of rectangular park

= 400 metre

Let, Perimeter of rectangular park be distance.

Now, we need to find time taken by deepak to complete one round of the rectangular park:

⟹ speed = distance/time

⟹ 10/9 = 400/time

⟹ 10 = 400/time * 9

⟹ 10 = 3600/time

⟹ time = 3600/10

⟹ time = 360 sec

Now, time taken by deepak to complete five round of the rectangular park:

⟹ Time = 360 * 5

⟹ Time = 1800 sec

Answer : Hence, Deepak take 1800 sec to complete five round of the rectangular park.

{More info : 1800 sec = 30 minute }