plotting – Comparison of a function in one plot

Secondly, I want to add the plot legends to the inside of the plot (to a suitable place).

 f(j_, k_, x_) :=Piecewise({{1, (j - 1)/4 k <= x && x <= j/4 k}, {0, True}});

  Plot({f(1, 2, x), f(1, 3, x), f(1, 4, x)}, {x, 0, 1.5},  PlotStyle -> { {Red, Thick}, {Blue, Thick, DotDashed}, {Green,Dashed} } , Frame -> True, GridLines -> Automatic, 
   PlotLegends -> {"f(1,2,x)", "f(1,3,x)", "f(1,4,x)"})

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