9. Of 1 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. 833, 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. 8-25 m. 12. What will 3000l. amount to in 12 years and 10 months, at 6 per cent. ? Ans. £5310. 13. What is the interest of 257l. 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. 74m. 15. What will 2791. 138. 8d. 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 per cent. per annum ? Ans. $488, 91 cts. 17. What will 730 dols. amount to at 6 per cent. in 5 years, 7 months and 12 days, or 12 of a year Ans. $975, 99cts. ? 18. What is the interest of 1825l. 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. COMMISSION, IS an allowance of so much per cent. to a factor or cor respondent abroad, for buying and selling goods for his employer. EXAMPLES. 1. What will the commission of 8431 10s. come to at 5 per cent. ? 2. Required the commission on 964 dols. 90 cts. at 24 per cent.? S. What may a factor demand on sion, for laying out 3568 dollars? BROKERAGE, Ans. $21, 71cts. 14 per cent. commisAns. 862, 44cts 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. ? 2. What is the brokerage upon 4125 dols. at or cents per cent.? Ans. $30, 93cts. 74m. 3. If a broker sells goods to the amount of 5000 dols. what is his demand at 65 cts. per cent. ? Ans. $32, 50cts. 4. What may a broker demand, when he sells goods to the value of 508l. 17s. 10d. and I allow him 1 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, merchandize, &c. which may happen from storms, fire, &c. EXAMPLES. 1. What is the insurance of 725l. 8s. 10d. at 12 per cent.? Ans. £90 13s. 74d. 2. What is the insurance of an East-India ship and cargo, valued at 123425 dollars, at 15 per cent. ? Ans. $19130, 87cts. 5m. 3. A man's house estimated at 3500 dollars, was insu red against fire, for 14 per cent. a year: what insurance 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. If the principal consists 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 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 shew the interest for one month, in shillings, and decimals of a shilling. EXAMPLES. 1. Required the interest of 541. for seven months and en days, at 6 per cent S. 10 days=1)5,4 Interest for one month. 7 37,8 ditto for 7 months. Ans. 39,6 shillings £1 19s. 7,2d. 12 7,2 2. What is the interest of 42l. 10s. for 11 months, at 6 per cent. ? £. s. 42:10= 42,5 decimal value. Therefore 4,25 shillings interest for 1 month. 11 Ans. 46,75 Interest for 11 mo. = £. s. d. 3. Required the interest of 947. 78. 6d. for one year, five months and a half, at 6 per cent. per annum. Ans. £8 5s. 1d. 3,5qrs. 4. What is the interest of 12l. 18s. for one third of a month, at 6 per cent. ♪ Ans. 5,16d. II. FOR FEDERAL MONEY. RULE. 1. Divide the principal by 2, placing the separatrix as usual, 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, &e. EXAMPLES. 1. What is the interest of 341 dols. 52 cts. for 7 months? 2. Required the interest of 10 dols. 44 cts. for 3 years 5 months and 10 days. 2)10,44 10 days=1) 5,22 Interest for 1 month. 41 months. Ans. 1881cts.=$18, 81cts. NOTE. To find the interest of any sum for 2 months, at 6 per cent. you need only call the dollars so many 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. 4 m. &c. which gives the following RULE II. Multiply the principal by half the number of months, d the product will shew the interest for the given time, cents and decimals of a cent, as above. |