Wed Dec 09 - The day this question was posted. And till now nobody cared/answered.
These forums are pretty much more like dead. (except for the Movies, TV celebrities part).
well the answer to you question :
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let the money he requires a day be x // we are assuming that he uses a fixed amount a day else this question is senseless.
let the number of days he took be y
=> 360=xy // the money each day x the days = 360
.:. x=360/y ___ @1
given that if he takes 4 more days he would have to use 3 Rs less a day
=> 360 = (y+4) (x-3)
=> 360 = xy -3y + 4x -12
=> 360 = (360/y)*y - 3y + (4*360/y) -12 --- putting @1 here
=> 360 = 360 -3y + (1440/y) -12
=> 360 - 360 + 12 = ((-3y^2 + 1440)/y)
=> 12=((-3y^2 + 1440)/y)
=> 12y = -3y^2 + 1440
=> 3y^2 + 12 -1440 = 0 // bringing all to the LHS
=> y^2 + 4y - 480 // dividing by 3
=> y^2 + 24y -20y - 480 =0
=> y(y+24) - 20(y+24) =0
=> (y-20) - (y+24) = 0
.:. y = 20 or y =-24
but whoah -24 cannot be a number of day - invalid insensible
so y =20 - he takes 20 days
putting y=20 in @1
.:. we get x=18.
Answer: So he takes 20 days spending Rs18 per day .