Read the passage below and solve the questions based on it.
Ujala Jewellers is a well known diamond jewellery shop. Owner of the shop has priced his diamond necklaces such that the cost varied as the square of the number of diamonds, for example the necklace placed at the first right top corner has 8 diamonds and costs Rs 1,60,000. There are lots of necklaces and the price of all necklaces have been found by the same method.
Vijay Shanker asked for diamonds in a necklace to be divided in the ratio of 5:3:2. Owner of Ujala Jewellers knew that he would suffer some loss. What is the % decrease in the price that he would incur, if he has to oblige Vijay Shanker?