In like manner may all the foregoing examples be solved, which I leave for the learner's exercise. Method 3, by Decimals. By the application of decimals we may easily discover the proportionable rate of 17, which is a common multiplier, to any given sum at that rate. A TABLE Of the Rates of 11. at any Rate per Cent. These rates of 11. are common multipliers for any sum given at the correspondent rate per cent, (the lesser denominations being first reduced to the decimal of 11.) which will plainly appear from the following Exa les I demand the annual interest of 2641, 16s. 3d. at 5 per cent. ? What is the commission on 1991. 3s. 6d. at 24 per cent ? 199.175 .025 995875 398350 4.979375 £4 19 7 Thus likewise may all the foregoing Examples be solved. A CHAP. V. INTEREST: NY sum of money being lent out upon consideration of receiving the same again, with a Premium from the Borrower for the use of it a certain time, is said to be put out at Interest; and the Interest is usually rated by. the 100% The sum lent out is called the Principal. Interest is the Premium or allowance for the use of the principal. The Rate is the interest of 1001. for 1 year. The Amount is the principal and its interest together. Interest is Simple or Compound. Simple Interest is that which arises from the principal only: As if T004, were lent for two years, the Simple Interest thereof for the two years will be 127. viz. ôl. due at the first year's end, and 67. due at the second year's end. Compound Interest is that which arises from the amount of the preceding year, vez from the principal and the interest likewise as it becomes due: So if 1001. be lent and forborne two year's at Compound Interest, the amount at the first year's end 1067. becomes a new principal; that is, Interest must be paid the second year not only for the 1007. Jent out, but likewise for the 61. interest due thereupon. SIMPLE INTEREST. Case I. To find the interest of any given sum for 1 year having the rate given. By having the rate given we have manifestly this proportion, 100: the rate :: the given sum: to its interest, which is solved in all cases by Chap. IV. Examples. 1. What is the interest of 2701. 108. 6d. at the rate of 50 cent? Answ. 131. 108. 6d. 13152 12 6 5 of 100, is 13 10 60% 20 13, 52625 £ 13 10 62% 10152 12 6130 2. What is the interest of 300l. 10s. for 1 year, at the rate of 8 cent. ann. ? 3 Tell me the interest of 3341. the rate of 6 cent. ann. ? Answ. 241. Os. 93d. 17s. 6d. for 1 year, at Answ. 201. 13s. 10d. 4. What is the interest of 246l. 18s. 10d. for 1 year, at 3 cent. ann. ? Answ. 71. 8s 14gd. 5. What is the interest of 2201. for a year, at 4 cent. per ann,? Answ. 8l. 16s. Gase II. To find the interest of any sum for any number of months, years, or years and months. Rule. 1. Find the inteerst of the given sum for 1 year. 2. For 2. For Years. Multiply the interest for 1 year by the number of years given. 3. For Months. Divide the months into aliquot parts of a year, and dis vide the interest of 1 year by the denominator or denomi nators, &c. as in Practice. Or thus: Find the rate or interest of 100%. for the given time. 100 its interest for the given time:: any sum: its in terest for the same time. Examples. Cast up the interest of 3487. 15% for 18 months, at 7 Answ. 361, 12s. 44d. cent. 1. 8. 7. s. d. 348.75 318 15 24 8 3 for 12 Mo.. .07' 7. Find the interest of 10007. for 21 months, at 8 per cent? Answ. 1401. 8. Tell me the interest of 10901. for 17 months at 6 per cent? Answ. 921. 13s. 9. How much is the interest of 175l. 10s. 6d, for 1 year and 7 months, at 6 per cent. per annum? Answ. 161. 13s. 5d. 10. What is the interest of 514/. for 1 year 7 months at 5 per cent. per annum? Answ. 417. 15s. 3d. 11. Cast up the inte.est of 8867. 16s, for 1 year 111⁄2 months, at 4 per cent per ann. ? Answ. 691. 9s. 32 d. 12. What is the interest of 479/ 188. for 2 years, at 4 per cent. per annum ? Answ. 431. 38. 91d. 13. What is the interest of 571 15s. for 8 months at 6 per cent. per annum? Answ. 221. 17s. 4‡d. 14. What is the interest per cent. per annum? of 300l. for 5 years, at 33 Answ. 641. 13s. 9d. A Contraction. Since 57. is of 100, whenever the interest of 100 is the interest of any sum at the same rate will be part of itself. But the interest of 100 is 5. 5 12 Wherefore when any sum at the said rates and time is given, divide it by 20, and the quotient is the interest required, Examples. 15. What is the interest of 3791. 15s, for 12 months, at 5 per cent.? 1. S. 20 3719 15 Answ. £.18 199 pence vaand lesser For the odd shillings and lue every 10s. equal to 6d. sums in proportion, i. e. 6s fd=4d. 5s3d. 4d: 6dd Is. 8d=1d. Is. 3d.=d. 10d.d 5d.d. 10s. 6d. 2d 28. 16. What is the interest of 4167. 128. 6d. for 10 months, at 6 per cent. per annum ? Answ. 201. 16s. 74d. 17. What |