Operation. The principal, Interest from March 1, 1822, to May 1, 1823, (14 mo.) Amount, Payment May 1, 1823, a sum greater than the interest, What was there due, August 31, 1828, interest at 6 per Ans. $115,77+ cent? $300 $ 12 $ 16 $108 $350 Due a new Int. of $556 from May 1, 1823, to June 16, 1824, (134mo.) Amount, Payment June 16, 1824, a sum greater than the interest due, 66 Pay't Sept. 17, 1825, less than the interest then due 66 66 Due June 16, 1824, forming a new principal, Due March 1, 1826, forming a new principal, Pay't Oct. 16, 1827, a sum greater than the interest then due, Due Oct. 16, 1827, forming a new principal, } Balance due, August 31, 1828. $500. January 1, 1830. 2. For value received, I promise to pay Peter Trusty, or order, five hundred dollars, with interest. WILLIAM PAYSON. On this note were the following Endorsements. received April 1, 1830, $12 $30 How much remains due August 16, 1831, interest at 6 per cent? Ans. $455,57, COMPOUND INTEREST Is that which arises both from the principal and interest; that is, when the interest is added to the principal at the end of the year, and on that amount the interest cast for another year and added as before; and so on for any number of years. Operation. $150=1st principal. 6 9,00 interest. RULE. Find the interest for 1 year, and add it to the principal; call this the amount for the first year. Find the interest of this amount and add it thereto for the amount of the second : and so on for any number of years. Subtract the original principal from the last amount, and the remainder will be the Compound Interest. $40 EXAMPLES. 1. What is the amount, and what the compound interest, of $150 for 3 years, at 6 per cent per annum? 8 $ 150 =1st principal added. 159,00 amount for the 1st year, or 2d principal. 6 interest. 9,5400 159, =2d principal added. 168,5400 amount for the 2d year, or 3d principal. 6 10,112400-interest. [Carried over.] [Operation brought up.] 10,112400 interest. 168,54 = $178,652400=amount for 3 years=$178 65cts. 2,4m. first principal subtracted. 150, $ 28,652400=compound int. for 3yrs. $28 65c. 2,4m. 2. What will $125 amount to in 4 years, at 6 per cent Ans. $157,80c. 9m+ per annum, compound interest? 3. What is the compound interest of $750 for 5 years, Ans. $207,21+ at 5 per cent? 4. What will be the amount of $410,50 for 3 years, at 6* Ans. $488,912+ per cent? 5. What is the compound interest of $500 for 3 years, at 6 per cent ? Ans. $95,50c. 8m. 6. What is the amount of $1000 for 4 years, at 6 per cent per annum, compound interest? 1 00 Ans. $1262, 47c. 6,98 m.+ Note. When there are months, or months and days, in the question, first find the amount for the years, and on that amount calculate the interest for the months, or months and days; this interest added to the amount for the years will give the amount required. 7. What will $148,25 amount to in 3 years and 6 months, at 6 per cent? Ans. $181,865+ $500 for 4 years 2 Ans. $114,08+ 8. What is the compound interest of months and 15 days, at 5 per cent ? BY DECIMALS. RULE. Multiply the principal continually by the amount of $1 or £1 for one year, at the given rate per cent, until the number of multiplications is equal to the given number of years. Thus, at 5 per cent, the amount for 1 year is 1,05; at 6 per cent, it is 1,06, &c. 1. What will be the amount of $500 for 3 years, at 6 per cent per annum? Thus, 500 x 1,06 x 1,06 × 1,06-$595,508, Ans. Or, find the amount of $1, for 3 years, at 6 per cent per annum. Note. Since the amount of 2 dols. will be just twice as much as 1 dollar, and 3 dollars 3 times as much as 1 dollar, and so on, it is evident 106 1,1236 amount for 2 yrs. that if we multiply the amount 1,06 67416 11236 of $1 by any given number of dollars, we have the amount for that number of dollars. 1,191016 amount for 3 yrs. Thus, the amount of $1 for 3 years, at 6 per cent, is 1,191016; this, multiplied by $500, gives the amount $595,508, the same as in example 1st. Hence we may have a Table showing the amount of £1 or $1, for any number of years, by which we may easily find the amount of any sum for the same time, by multiplying the amount taken from the Table by the given sum. 1 23456789 A TABLE, Showing the amount of $1, or £1, for any number of years, not exceeding 20, at 5 and 6 per cent, Compound Interest. YEARS. 15 PER CENT. 6 PER CENT. YEARS. 5 PER CENT. 6 PER CENT. 10 1,06 amount for 1 year. 636 Answer. Amount for 5 years, Leaves the Compound Interest, 1,89829 2,01219 2,13292 2,26090 2,07893 2,39655 2,18287 2,54727 2,29201 2,69277 2,40661 | 2,85433 2,52695 3,02559 2,65329 3,20713 3. What is the amouut, and what the Compound Interest, of $350 for 5 years, at 6 per cent? Am't of $1 for 5yrs. at 6 per cent, by the Table 1,33822 Multiply by the principal, X 350 6691100 401466 468,37700 350 $118,377 4. What is the amount, and what the Compound Interest of $311,25 for 6 years, at 5 per cent? Ans. } $417,103 Amount. $105,85,3 Compound Interest. [The learner may work all the preceding examples in Compound Interest by the foregoing Table of Amounts, if necessary for further practice.] Note. Any sum at 6 per cent, Simple Interest will double itself in 16 years 8 months; and at Compound Interest, in 11 years 8 months and 22 days. DISCOUNT Is an allowance made for the payment of any sum of money before it becomes due. After the discount is deducted, the remainder is the present worth; or, such a sum as, if put at interest, at the given rate and time, would amount to the given sum. RULE. 1. As the amount of $100, or £100, at the given rate and time, is to the interest of 100, at the same rate and time, so is the given sum to the discount. Subtract the discount from the given sum, and the remainder is the present worth.-Or by |