9. Of i dollar for 12 years, at 5 per cent.! Ans. 60cts. 10. Of 215 dollars 34 cts. for 4 and a half years, at 3 and a half per cent.! Ans. $33,91cts. 6m. 11. What is the amount of 324 dollars, 61 cents, for 5 years and 5 months, at 6 per cent.? Ans. $430,10cts. 861 12. Whạt will 30001. amount to in 12 years and 10 months, at 6 per cent.? Ans. £5310. 13. What is the interest of 2571. 5.s Id. for 1 year and 3 quarters, at 4 per cent ? £18 Os.ld: 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. 7m. 15. What will 2791. 13s. 8d. amount to in 3 years and a half, at 51 per cent. per annum ? Ans. £331 1s. Od 16. What is the amount of 341 dolls. 60 cts. for 5 years and 3 quarters, at 7 and a half per cent. per annum ? Ans. $488,91 } cts. 17. What will 730 dollars amount to at 6 per cent. in 5 years, 7 months and twelve days, or Aris. $975,99cts. 18. What is the interest of 18251. at 5 per cent. per annum, from March 4th, 1796, to March 29th, 1799, (allowing the year to contain 365 days ?) Ans. £280. Note.-The Rules for Simple Interest serve also to calculate Commission, Brokerage, Insurance, or any thing else estimated at a rate per cent. 12 of a year? 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. per cent. ? 6100 £42 3s. 6d. 2. Required the commission on 964 dols. 90cts. at 24d. Ans. $ 21, 71 cis 3. What may a factor demand on 18 per cent, commission for laying out 3568 dollars ? Ans. $62. 44cts, BROKERAGE Isan 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 fent ? 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 8 4 20 10,08 12 Ans. £2 10 0 1,00 2. What is the brokerage upon 4125 dols. at for 75 pents per cent. ? Ans. $30, 93cts. 7m. 3. If a broker sells goods to the amount of 5000 dols. what is his demand at 65 cts. per cent. 3 Ans. $89, 50cts. 4. What may a broker demand, when he sells goods to the value of 5081. 175. 10d. and I allow him 11 per cent? Ans. £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, merchandise, &c. which may happen from storms, fire, & C. EXAMPLES. 1. What is the insurance of 7251. 8s. 10d. at 12% per cent. ? Ans. £90 135.74d. 2. What is the insurance of an East-India ship and cargo, valued at 123425 dollars, at 154 per cent. ? Ans. $19130, 87 cts. 5m. 3. A man's house estimated at 3500 dollars, was in sured against fire, for 14 per cent. a year : what insur, ance did he annually pay? Ans. $61, 25cts. SHORT PRACTICAL RULES, For calculating Interest at 6 per cent. either for months, or months and days. I. FOR STERLING MONEY. RULE. 1. If the principal consists of pounds only, cut off the unit figure, and as it then stands, it will be the inte rest for one month, in shillings and decimal parts. 2. If the principal consists 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 541. for seven months and ten days, at 6 per cent. 10 dayx})5,4 Interest for one month. 7 37,8 ditto for 7 months. 1,8 ditto for 10 days. Ans. 39,6 shillings=£1 19s. 7,2d. 12 7,2 2. What is the interest of 421. 10s, for 11 months, at 6 per cent ? £. £. 42 10: 42,5 decimal value. Therefore 4,25 shillings interest for 1 month. 11 €. 8. d. Ans. 46,75 Interest for 11 mo. = 2 6 9 3. Required the interest of 941 78. 6d. for one year, five months and a half, at 6 per cent. per annum? Ans. £8 53. 1d. 3,5qrs. 4. What is the interest of 122 18s. for one third of a month, at 6 per cent. ? Ans. 5,16d. II. FOR FEDERAL MONEY. RULE 1. Divide the pscipal by 2, placing the separatı ix as asual, and the quotient will be the interest for one month in cents, and decimals of a cent; that is, the figures at the left of the separatrix will be cents and those on the right decimals of a cent. 2. Multiply the interest of one month by the given number of months, or months, and decimal parts thereof, or for the days, take the even parts of a month, &c EXAMPLES. 1. What is the interest of 341 dols. 52 cts. for 7 months ? 2)841,52 Or thus, 170,76 Int. for 1 month. 170,76 Int. for 1 month. X7,5 months, 7 글 85380 1195,32 do, for 7 mo. 119332 85,38 do. for mo. $ cts. m. 1230,700cts.=12,807 0,70 Ans. 1280,7cts.=$12, 80cts. Ym. 2. Required the interest of 10 dols. 44 cts for 3 years, 3 months and 10 days, 2)10,44 ļo days=}) 5,22 Interest for 1 month, 41 months. 5,22 208,8 214,02 ditto for 41 months. 1,74 ditto for 10 days. 215,76cts. Ans. =$2, 15cts. 7m. ti 3. What is the interest of 342 dollars for ļ 1 months ! The 1 is 171 Interest for one month, Ans. 1881 cts.=$18, 81 cts. Notr.–To find the interest of any sum for 2 months, at 6 per cent. you need only call the dollars so mang cents, and the inferior denominations decimals of a cent, and it is done : Thus, the interest of 100 dollars for two months, is 100 cents, or 1 dollar ; and $25, 40 cts. is 25 cts. 4m. &c. which gives the following RULE II. Multiply the principal by half the number of months, and the product will show the interest for the given time, in cents and decimals of a cent, as above. |