Question

A man walks from his house to his daughter's schoolat the speed of 3 kilometre per hour and return back at the speed of 4 km per hour. if he takes 21 minutes for double journey, then find the distance between his house and his daughter's school?
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Answer 1

Step-by-step explanation:

Let the distance between house and school =D km

Since, Time = distance / time

d/3 + d/4= 21/60

7d / 12= 21 /60

d= 3/5 simplify

d=0.6 km

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