A rectangular portion of an airport runway was getting repaired for which an estimate was made on the basis of a 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 increase in the cost of the repair work to the extent of 15%. What was the overall percentage increase in the cost of repair over the estimate? (SSC CHSL-2018)
Correct answer is option 'A'. Can you explain this answer?