The length of a rectangular plot is 20 metres more than its breadth. If the cost of fencing the plot @ 26.50 per metre is Rs. 5300, what is the length of the plot in metres?

$$\eqalign{ & {\text{Let}}\,{\text{breadth}} = x\,{\text{metres}} \cr & {\text{Then,}}\,{\text{length}} = \,\left( {x + 20} \right)\,{\text{metres}} \cr & {\text{Perimeter}} = {\frac{{5300}}{{26.50}}} m = 200m \cr & \therefore 2\left[ {\left( {x + 20} \right) + x} \right] = 200 \cr & \Rightarrow 2x + 20 = 100 \cr & \Rightarrow 2x = 80 \cr & \Rightarrow x = 40 \cr & {\text{Hence,}}\,{\text{length}} = x + 20 = 60m \cr} $$