Answers

2014-07-13T12:46:33+05:30
3km/hr :)

3/x - 3/x+1 =15( in min so convert to hrs by dividing by 60)

this should be your equation 



best?
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2014-07-13T13:16:47+05:30
3kmph. He was walking 3kmph so if he walked 1kmph faster it wold have taken him 15min less
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