A rectangular portion of an airport runway was getting repaired for which an estimate was made on the basis ofa rate ₹R per square unit. But while doing the work, the length of the portion got increased by 10% and the breadth by 8%. Over and above this, there was an increasein the cost of the repair work to the extent of 15%. What wasthe overall percentage increase in the cost of repair over the estimate?

Overall percentage increase in area of reactangle = $$x\pm y\pm\frac{xy}{100}$$ where x = lenght and y = breadth

                                                                           =$$10+ 8+\frac{80}{100}=18.8$$

Now there was a cost of extent = 15% so, 

Overall percentage increase in the cost of repair over the estimate=$$x\pm y\pm\frac{xy}{100} $$

                                                                                                    =$$18.8+15+\frac{18.8\times15}{100}$$=44.14