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ANOTHER METHOD. Write down the given principal in cents, which multi ply 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 6 per cent. ? Principal 7365 cents.
Ans. 441,90cts.=441% cts. or $4, 41cts. 9m. 10. Required the interest of $85, 45cts. fer a year, at 7 per cent. ?
Aus 598, 15 cents,-$5,98cts 117
To find the simple interest of any sum of money, for any number of years, and parts of a year.
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 morths 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 aliq'lot parts of the
By allowing the month to be 30 days, and taking aliquot parts thereof, you will have the interest of any onlinary sum sufficiently exact for commou use; but if the sum be very large, you may say,
As 365 days is to the interest of one year : •80 is the giroa aomler of clayu; to the interest required,
1. What is the interest of 751. 8s. 4d. for 5 years and 2 months, at 6l. per cant. per annum ?
d. 75 8 4
d. 6 2mo.-*)4 10 6 Interest for 1 year.
5 4152 10 0 20
22 126 do. for 5 years.
15 1 do. for two montns. 10150 12
7 7 Ans.
2. What is the interest of 64 dollars 58 cents for S years, 3 months, and ten days at 5 per cent. ?
322,90 Interest for 1 year in cents, per 3
968,70 do. for 3 years. 4 mo.
} 107,63 do. for 4 months. 1 mo. 26,90 do. for 1 month. 10 days, $ 8,96 do. for 10 days.
per cent. ?
Ans. 1112,19-1112cts. or $ 11, 12c. 130m. 3. What is the inte.est of 789 dollars for 2 years, at 6
Ans. $ 94, 68cts 4. Of 37 dollars 50 cents, for 4 years, at 6 per cent. per annum ?
Ans. 900cts. or $9. 5. Of 325 dollars 41 cts. for 3 years and 4 months, at 5 per cent. ?
Ans. $54, 23cts. 5m. 6. Of 325l. 12s. 3d. for five years at 6 per cent. ?
Ans. €97 138. 8d. 7. Of 1741. 10s. 6d. for 3 and a half years at 6 per cent. ?
Ans. £36 135. 8. Or 1501. 165. 8d. for 4 ycars and 7 months, at 6 per cent, ?
Ans. 441 98.78
9. Of 1 dallar for 12 years at 5 per cent. ?
Ans. 60cts. 10. Of 215 dollars 34 cts. for 4 and a half years, ats and a half per cent. ?
Ans. $33, 91cts. 6m. 11. What is the amount of 324 collars, 61 cents, for 5 years and 5 months, at 6 per cent. ?
Ans. $430, 10cts. 88 m. 12. What will 3000l. amount to in 12 years and 10 months at 6 per cent. ?
Ans. £3310. 13. What is the interest of 2571. 55. id. for 1 year and 3 quarters, at 4 per cent. ? Ins. £18 Cs. ld. 3qrs.
14. What is the interest of 279 dollars, 87 cants for 2 years and a half, at 7 per cent. per annum ?
ins. $48, 37cts. 74m. 15. What will 2791. 13s. $d. amount to in 3 years and a half at 54 per cent. per annum?
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
Ains. $488, 91 cts 17. What will 730 dols. amount to at 6 per cent. in 5 years, 7 months and 12 days, or 36 of a year ?
Ans. $975, 99cts. 18. What is the interest of 1825l. at 5 per cent. pes annum, from March 4th, 1796, to March 29th, 1799, (allowing the year to contain 365 days ?) ne. £280.
Note.-The Rules for Simple Interest serve also to calculate Commission, Brokerage, Insurance, or any thing else estimated at a rate per cent. ?
COMMISSION, IS an allowance of so much per cent., to a factor or con respondent abroad, for huying and selling gorils for his employer
1. What will the comruission of $131. 108. come to at 5 per cent. $
per cent. ?
6100 £42 33. 60. 2. Required the commission on 964 dols. 90cts. at 24
71618. 3. What pay a factor demand on la per cent. conmis. sion for laying out 3568 dollars ? Ans. $62, 44cts.
BROKERAGE, IS an allowance of so much per cent. to personas assisting merchants, or factors, in purchasing or selling goods.
1. What is the brokerage of 7501. Ss. 4d. at Cs. 8d. por cent. ?
d. 750 8 4 Here I first find the brokerage at i 1 pound per cent. and then for the
given rate which is } of a pound.
6 8=:)7 10 1
Ans. £2,10 0 1}
£. s. d. grs,
1,00 2. What is the brokerage upon 4125 dols. at or 75 cents per cent. ?
Ans. $30, 93cts. 7}m. 3. If it broker sells goods to the amount of 5000 duls. what is his demand at 65 cts. per cent. ?
Ann $32, 50cte.
4. What may a broker demand, when he sells goods in the value of 3081. 17s. 10d. and l allow him li per cent.
Ins. 7 12s. 8d.
INSURANCE, IS a premium at so much per cent. allowed to persons and offices, for making good the loss of ships, houses, merchandize, &c. which may happen from storms, fire, &c.
1. What is the insurance of 725l. $s. 10d. at 124 per cent. ?
Ans. £90 13s. 7 d. 2. What is the insurance of an East-India ship and care go, valued at 123425 dollars, ai 15 per cent. ?
Ins. $19130, 87rts. 5m. 3. A man's house estimated at 3500 dollars, was insure ed against fire, lor 13 per cent. a year : what insurance did he annually pay ?
Ans. $61, 23¢ts.
SHORT PRACTICAL RULES,
or months and lays.
RULE. 1. If the principal consists of pounds only, cut off the unit figure, and as it then stands i will be the interest for one month, in shillings and decimal parts.
2. If the principal cousists of nourds, shillings, &c. re. duce it to its decimal value; then move the decimal point one place or figure, further tow.rds the left hand, and as the decimal then stands, it will shew the interest for one month in shillings and decimals of a shilling
1. Required the interest of 541. for seveo montira ang ten days, at 6 per cent.