EXAMPLES.

1. What is the commission on the purchase of goods, the invoice of which amounts to 1250 dollars, at 24 per cent.?

Ans. $31.25.

2. What must I allow my correspondent for selling goods to the amount of $4325-75 at a commission of 5 per cent.?

Ans. $216.2875.

BUYING AND SELLING STOCKS.

STOCK is a general name for the capitals of trading companies, or of a fund established by government, the value of which is variable.

RULE.--If the stock be above par, that is, when 100 dollars of stock are worth more than 100 dollars, multiply the given sum by its value per cent. over 100 per cent. and divide the product by 100; then add the quotient and given sum together, the amount will be the value required.

If the stock be below par, that is, when 100 dollars of stock are worth less than 100 dollars, multiply the given sum by its value per cent. less than 100 per cent. and divide the product by 100; then subtract the quotient from the given sum, the remainder will be the value required.

EXAMPLES.

1. What is the value of $7500 United States Bank Stock, at 1121 per cent.?

Ans. $8437.50.

2. What is the value of $5400 of Stock, at 97 per cent.?

Ans. $5238.

210. What are Stocks?--211. What is the rule for finding the value of any kind of stock, the value per cent. being given?

INSURANCE....SIMPLE INTEREST BY DECIMALS. 119

INSURANCE.

INSURANCE is a security by contract, to indemnify for a specified sum, the insured for such loss or damage as may happen to the property, for a limited time.

The premium is the sum paid by the insured for the insurance of his property, and is generally at so much per cent.

RULE.-Multiply the sum to be insured by the rate per cent. and divide the product by 100 ;-the quotient will be the premi

um or answer.

EXAMPLE.

What will be the annual premium for insuring a house against loss by fire, valued at $5600, at 3 per cent.?

Ans. $42.

SIMPLE INTEREST BY DECIMALS.

A TABLE OF RATIOS FROM ONE DOLLAR, &c. TO TEN DOLLARS. Ratio is the simple interest of $1 or £1 for one year, at the rate per cent. agreed on, and is found by dividing the rate by 100, and reducing it to a decimal. Thus 106, and 150

==.05.

212. What is Insurance?- -213. What is the premium ?——214. What is the rule.

for finding the premium, the rate per cent. being given?

A TABLE for the ready finding of the decimal parts of a year, equal to any number of months and days, allowing 12 months, or 365 days to

1. Multiply the principal by the ratio, the product will be the interest for one year.

2. To find the interest for more years than one, multiply the interest of one year by the given number of years, aud the product will be the interest for that number of years.

3. To find the interest for months, or months and days; multiply the interest of one year by the decimal parts which are equal to the given number of months, or months and days, and the product will be the interest for that time.*

EXAMPLES.

1. What is the interest and amount of $475.50 for 4 years, 9 months, 25 days, at 6 per cent.?

*This rule is a contraction of the general rule for simple interest.

215. What is the rule for computing simple interest by decimals?

2. If a factor sell a cargo for me, to the amount of $1750, on commission at 24 per cent. and purchase me another cargo of the value of $2500, on commission at 13 per cent.; what will his commission on both cargoes amount to?

Ans. $83.125.

COMPOUND INTEREST.

COMPOUND INTEREST is that which arises from the interest being added to the principal at the end of each year, and making the amount the principal for the next succeeding year.

RULE. Find the interest of the given sum for one year, and add it to the principal, the amount is the principal for the second year; then find the interest of that amount, and add as before, and thus proceed for any number of years required.

216. What is Compound Interest?—217. What is the rule for calculating com pound interest?

૨

Subtract the first principal from the last amount, and the remainder will be the compound interest for the whole time.*

EXAMPLES.

1. What is the compound interest of $680 for 4 years, at 6 per cent?

680 given sum or first principal.
40-80 interest of do. for one year.

720 80 amount or principal for 2nd year.
43.248 interest of do.

764.048 amount or principal for 3rd year.
45.843 interest of do.

809 891 amount or principal for 4th year.
48.593 interest of do.

858-484 amount for 4 years.

680.000 first principal subtracted.

Ans. $178.484 compound interest for 4 years.

2. What is the compound interest of £400, for 3 years, at 5 per cent.? Ans. £63 15.

3. What will be the amount and compound interest of 1000 dollars for 5 years, at 6 per cent.?

* It is not usually necessary to carry the work beyond mills; therefore, when the figure next beyond mills, at the right is 5 or more than 5, increase the number of mills 1; when it is less than 5, it may be omitted, and the result will be exact enough for common purposes.