<PRE><B>Question 999968</B>
let speed of slower hiker be x
speed of faster is x=3

Time taken by slower hiker = 21/x

time taken by faster hiker = 30/(x+3)

Time taken by faster hiker - time taken by slower hiker = 1/4

{{{30/(x+3)-21/x =1/4}}}




multiply equation by 4x(x+3)

30*4x -21*4(x+3) = 4x(x+3)/4

120x-84x-252 = x^2+3x

x^2 +3x+84x-120x+252=0

x^2-33x+252=0
x^2-21x-12x+252=0

x(x-21)-12(x-21)=0

(x-12)(x-21)=0

x=12 OR 21










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