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ANOTHER METHOD.

Write down the given principal in cents, which multiply. by the rate, and divide by 100 as before, and you will have the interest for a year, in cents, and decimals of a cent, a follows:

9. What is the interest of $73, 65 cents for a year, at € per cent.?

Principal 7365 cents.

6

Ans. 441,90-441 cts. or $4, 41 cts. 9 m.

10. Required the interest of $85, 45 cts. for a year, at " per cent.?

Cents.

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To find the simple interest of

any sum of money,

number of years, and parts of a year.

for ary

GENERAL RULE.-1st. Find the interest of the given sum for one

year.

2d. Multiply the interest of one year by the given number of years, and the product will be the answer for that time.

3d. If there be parts of a year, as months and days, work for the months by the aliquot parts of a year, and for the days by the Rule of Three Direct, or by allowing 30 days to the month, and taking aliquot parts of the same." *

By allowing the month to be 30 days, and taking aliquot parts thereof, you will have the interest of any ordinary sum sufficiently exact for common but if the sum be very large, you may say,

use;

As 365 days is to the interest of one year so is the given number of days to the interest required

EXAMPLES.

1. What is the interest of 751. 8s. 4d. for 5 years and 2 months, at 67. per cent. per annum?

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62 mo. 14 10 6 Interest for 1 year.

£. S. d. 75 8

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2. What is the interest of 64 dollars 58 cents for 3 years, ♦ months, and 10 days, at 5 per cent.?

$ 64,58

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Ans. 1112,19=1112cts. or $ 11, 12c. 1m. 3. What is the interest of 789 dollars for 2 years, at 6 per cent. ? Ans. $94, 68 cts. 4. Of 37 dollars 50 cents for 4 years, at 6 per cent. per annum? Ans. 900 cts. or $9. 5. Of 325 dollars 41 cts. for 3 years and 4 months, at 5 per cent.? Ans. $54, 23 cts. 5 m. 6. Of??51. 12s. 3d. for five years, at 6 per cent.?

Ans. £97 13s. 8d.

cent.?

7. Of 1. 47. 10s. 6d. for 3 and a half

years, at 6 per Ans. £36 13s.

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8. Of 1507. 16s. Sd. for 4 years and 7 months, at 6 per

cent.?

Ans. £41 9s. 7d.

9. Of 1 dollar for 12 years, at 5 per cent.?

Ans. 60 cts. 10. Of 215 dollars 34 cts. for 4 and a half years, at ¶ and a half per cent. Ans. $33, 91 cts. 6m. 11. What is the amount of 324 dollars 61 cents for years and 5 months, at 6 per cent.?

Ans. $430, 10 cts. 825m. 12. What will 30007. amount to in 12 years and 10 months, at 6 per cent.?. Ans. £5310. 13. What is the interest of 2571. 5s. 1d. for 1 year and 3 quarters, at 4 per cent.?

Ans. £18

Os. 1d. 3qrs. 14. What is the interest of 279 dollars 87 cents for 2 years and a half, at 7 per cent. per annum? Ans. $48, 97cts. 7≥m. 15. What will 2797. 13s. 8d. amount to in 3 years

half, at 5 per cent. per annum?

and a

Ans. £331 1s. 6d.

16. What is the amount of 341 dols. 60 cts. for 5 years and 3 quarters, at 7 and a half per cent. per annum ? Ans. $488, 911⁄2 cts. 17. What will 730 dols. amount to at 6 per cent. in 5 years, 7 months, and 12 days, or of a year?

Ans. $975, 99 cts. 18. What is the interest of 18251. at 5 per cent. per an. num, from March 4th, 1796, to March 29th, 1799, (allow ing the year to contain 365 days?)

Ans. £280.

NOTE. The Rules for Simple Interest serve also to calculate Commission, Brokerage, Ensurance, or any thing else estimated at a rate per cent.

COMMISSION,

IS an allowance of so much per cent., to a factor or correspondent abroad, for buying and selling goods for his employer.

EXAMPLES.

1. What will the commission of 8431. 10s. come to at 5 per cent. ?

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4 Required the commission on 964 dols. 90 cts. at 21 perent. ? Ans. $21, 71 cts. 3. What may a factor demand on 13 per cent. commission for laying out 3568 dollars? Ans. $62, 44 cts

BROKERAGE,

IS an allowance of so much per cent. to persons assisting merchants, or factors, in purchasing or selling goods.

EXAMPLES.

1. What is the brokerage of 750l. 8s. 4d. at 6s. 8d. per cent. ?

£ s. d.

750 8 4
1

Here I first find the brokerage at 1 pound per cent. and then for the given rate, which is of a pound.

7,50 6 4

20

10,08

12

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2. What is the brokerage upon 4125 dols. at 3 or 75 cents per cent. ? Ans. $30, 93 cts. 71 m. 3. If a broker sell goods to the amount of 5000 dollars, what is his demand at 65 cts. per cent.?

Ans. $32, 50 cts.

4. What may a broker demand, when he sells goods to the value of 5087. 17s. 10d. and I allow him 1 per cent. } Ans. £7 12s. 8d.

ENSURANCE,

IS a premium at so much per cent. allowed to persons and offices, for making good the loss of ships, houses, merchandise, &c. which may happen from storms, fire, &c.

EXAMPLES.

1. What is the ensurance of 7251. 8s. 10d. at 12 per cent.? Ans. £90 13s. 7id. 2. What is the ensurance of an East-India ship and car go, valued at 123425 dollars, at 15 per cent. ?

ARS. $19130, 87 cts. 5 m. 3. A man's house estimated at 3500 dols., was ensured against fire, for 13 per cent. a year: what ensurance did he annually pay? Ans. $61, 25 cts.

Short Practical Rules for calculating Interest at 6 per cent. either for months, or months and days.

1. FOR STERLING MONEY.

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RULE.-1. If the principal consist of pounds only, cut off the unit figure, and as it then stands it will be the interest for one month, in shillings and decimal parts.

2. If the principal consist of pounds, shillings, &c. reduce it to its decimal value; then remove the decimal point one place, or figure, further towards the left hand, and as the decimal then stands, it will show the interest for one month in shillings and decimals of a shilling.

EXAMPLES.

1. Required the interest of 547. for seven months and ten days, at 6 per cent.

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