Once three friends A B and C went to a shop to buy a lamp .the shop keeper was not on the shop.But a servant of the shop was there ,they asked for the cost he said 60 bucks.They all agreed and paid 20rs. each.Now they came back after taking the lamp.When shopkeeper came back,he asked --was there any customer ? The servant told him about the three person.Then he recognized that they three were their friend and they should have been given a discount.so he told the servant to go to them and return them 10 bucks.The servant was a bit weak in maths .He kept 4 bucks with him self and gave away 6 bucks to A B and C .they all were happy and shared 2 bucks each.Now they got the lamp cost them 18 bucks each.The lamp cost them 18X3=54 bucks.and the servant also took 4bucks with him.total being 58 bucks.Now the question is
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