Question

A dishonest shopkeeper has two false balances. One balance wieghs 10% more while buying the goods and other weighs 10% less while selling the goods then what is his gain percent just by weighing?

Answer 1

Shopkeepers gain just by weighing is `22.22%`

Explanation:

Assume that theshopkeeper bought `x` units of goods i.e. actual weight of goods.

As the balance used to buy goods weighs `10%` more, he actually bought `x xx 110/100=1.1x` weight units i.e. although the shopkeeper paid for `x` units, he actully bought `1.1x` units by weight.

Now he has `1.1x` units of goods, but for selling he uses another balance, which actually measures `10%` less i.e. `1-0.10=0.9` units for each unit weight of goods sold.

So while selling `1.1x` becomes `(1.1x)/0.90=1.2222...` units.

Hence, shopkeepers gain just by weighing is `22.22%`