If you go to shop with your 3 frd if you buy clock ₹60 so u share 20 -20 rupees among you so all 3 frds contributed but when the s

If you go to shop with your 3 frd if you buy clock ₹60 so u share 20 -20 rupees among you so all 3 frds contributed but when the shopkeeper came he said the clock cost is 50 so give 10 back but there was 3 person so how they distribute among them 10 so they give 4 to shopkeeper distribute 6 among them so each one get 2 back so we have 18+18+18=54+4 that they have given to shopkeeper so it is 58 but total money was 60 were was 2