Question

I walk to a town at 3and half kmph,rest there for 45 minutes and ride back at 7 and half kmph.find the distance to the town,if the total time spentby me is 6hrs 37 minutes

Answer 1

Since the distance covered is same,
Average speed = 2*a*b/(a+b), where a & b are respective speeds of to and fro journey.
Avg speed = 2*3.5*7.5/(3.5+7.5) = 4.77 km/hr (approx.)
Total time(including rest) = 6 hrs 37 minutes.
Rest = 45 minutes
Hence, travel time = 6 hrs 37 minutes - 45 minutes = 5 hrs 52 minutes = 5 52/60 = 5 13/15 hrs.
D = S * T = 4.77 * 5 13/15 = 4.77 * 88/15 = 28 Km
This is the total distance, that is, to and fro.
Hence distance to town = 28/2 = 14 Km.
Hope it helps.

Answer 2

Answer:

Since the distance covered is same,

Average speed = 2*a*b/(a+b), where a & b are respective speeds of to and fro journey.

Avg speed = 2*3.5*7.5/(3.5+7.5) = 4.77 km/hr (approx.)

Total time(including rest) = 6 hrs 37 minutes.

Rest = 45 minutes

Hence, travel time = 6 hrs 37 minutes - 45 minutes = 5 hrs 52 minutes = 5 52/60 = 5 13/15 hrs.

D = S * T = 4.77 * 5 13/15 = 4.77 * 88/15 = 28 Km

This is the total distance, that is, to and fro.

Hence distance to town = 28/2 = 14 Km.

Hope it helps.

Step-by-step explanation: