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, as follows:

9. What is the interest of $73, 65 cents for a year, at 0 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.
Principal 8545

7

Ans. 598, 15 cents,=$5,98 cts. 14M.

4

CASE II

To find the simple interest of any sum of money, for any

number of years, and parts of a year.

ar

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 Role 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 use ; but if the sumn be very large, you may say,

Aš 365 days : is to the interest of one year : : 80 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 61. per cent. per annum? £. S.

d.
75 8 4

£. s. d.
6 2 mo.=*)4 10 6 Interest for 1 year.

5
4|52 10 0
20

22 12 6 do. 5 years.

0 15 1 do. for two months.
10,50
12

£23 77 Ans.

6100 2. What is the interest of 64 dollars 58 cents for 3 years, 5 months, and 10 days, at 5 per cent. ?

$ 64,58

5

322,90 nterest for 1 year in cents, per 3

[Case L.

1 mo.

per cent. ?

968,70 do. for 3 years. 4 mo.

Ž | 107,63 do. for 4 months.

26,90 do. for 1 month. 10 days, } 8,96 do. for 10 days.

Ans. 1112,19=1112cts, or $ 11, 12c. 11.m. 3. What is the interest of 789 dollars for 2 years, at 6

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

Ans. $54, 23 cts. 5 m. 6. Of ??51. 12s. 3d. for five years, at 6 per cent. ?

Ans. £97 13s. 8d. 7. Of 1.41. 10s. 6d. for 3 and a half years, at 6 per cent.?

Ans. £36 13s. 28. Of 1501. 168. 8d. for 4 years and 7 months, at 6 per cent. ?

Ans. £41 9s. 70.

per cent. ?

per cent. ?

9. Of i dollar for 12 years, at 5

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. 8707m. 12. What will 30001. amount to in 12 years and 10 months, at 6

per
cent. ?

Ans. £5310. 13. What is the interest of 2571. 5s. ld. for 1

year

and 3 quarters, at 4 per cent. ? Ans. £18 Os. Id. 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. 71m. 15. What will 2791. 138. 8d. amount to in 3 years and a half, at 54 per cent. per annum?

Ans. £331 ls. 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. $483, 911cts. 17. What will 730 dols, amount to at 6 per cent. in 5 years, 7 months, and 12 days, or V's 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.

W

1. What will the commission of 8431. 108. come to at & Der cont. ?

3150

12 310. ar and 6100

£42 3s. 6d, grs.

2. Required the commission on 964 dols. 90 cts. at 21 for? per cent. ?

Ans. $21, 71 cts. 3. What may a factor demand on 13 per cent. commismu sion fur laying out 3568 dollars ? Ans. $62, 44 cts. and a

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 7501. 8s. 4d. at 6s. 8d. per cent. ?

£ s. d.
750 8 4 Here I first find the brokerage at 1 pound
-1 per cent. and then for the given rate,

which is of a pound.
7,50 84
20

d.

qrs.

6.8=})7 10 1 0
10,08
12

Ans. £2 10 0 1}

30. cal

S. d.

f. s.

Thing

cor

+ 1,00

sem

per cent. ?

2. What is the brokerage upon 4125 dols. at or 75 cents

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.

atd

4. What may a broker demand, when he sells goods to the value of 5081. 178. 10d, and I allow him if 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. 83. 10d. at 12} per cent. ?

Ans. £90 13s. 77d. 2. What is the ensurance of an East-India ship and cars go, valued at 123425 dollars, at 151 per cent. ?

Ans. $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.

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 shilo ling.

EXAMPLES.

1. Required the interest of 541. for seven months and ten days, at 6 per cent.