Retail merchants, in buying goods by wholesale, buy a great many
articles by the dozen, such as boots and shoes, hats and caps, and
notions of various kinds; now the merchant, in buying, for instance,
a dozen hats, knows exactly what one of these hats will retail for in
the market where he deals; and unless he is a good accountant, it
will often take him some time to determine whether he can afford to
purchase the dozen hats and make a living profit by selling them by
the single hat; and in buying his goods by auction, as the merchant
often does, he has not time to make the calculation before the goods
are bid off. He therefore loses the chance of making good bargains by
being afraid to bid at random, or if he bids, and the goods are cried
off, he may have made a poor bargain by bidding thus at a venture.
It then becomes a useful and practical problem to determine instantly
what per cent. he would gain if he retailed the hat at a certain
price, to tell what an article should retail for to make a profit of
20 per cent.
_Rule.--Divide what the articles cost per dozen by 10. which is done
by removing the decimal point one place to the left._
For instance, if hats cost $17.50 per dozen, remove the decimal point
one place to the left, making $1.75, what they should be sold for
apiece to gain 20 per cent, on the cost. If they cost $31.00 per
dozen, they should be sold at $3.10 apiece, etc.