1 yr. 8 mo. ?-150. For 4 yrs. 2 mo. ?-375. For 6 yrs. 6 mo. ?585. A. $1365. 6. What is the amount of $75 for 2 yrs. 6 mo. ?-8625. Of $2502-28750. Of $800 ?-920. Of $95?-10925. Of $650? 74750. A. $2150,50. 7. What is the amount of $615,75 for 5 yrs. ?-800475. For 11 yrs. 1 mo. ?-1025223. For 7 yrs. 2 mo. ?-880522. A. $2706,22+. 8. What is the interest of $7650 for 3 yrs. 3 ino. ?-149175. For 3 yrs. 4 mo. ?-1530. For 6 yrs. 6 mo. ?-298350. For 2 yrs. 2 mo. ?-99450. A. $6999,75. 9. What is the amount of $7,50 for 10 yrs. 1 mo. ?-12037. For 2 yrs. 3 mo. ?-8512. For 1 mo.?-7537. For 11 mo. ?7912. For 1 vr. 7 mo. ?-8212. A. $44,21 +. T LXII. Since days are always either 30ths of a month, or some greater part, as halves, 3ds, 4ths, 5ths, &c.; thus, ì day; 2 days— , which, being reduced to its lowest terms, is; 3 days, or; 5 days, or ; 20 days, or ; it follows, that, if these parts be diminished in the same proportion as the months, that is, if half the fractional part be taken for a multipiier, the product will express the interest for the days in cents, or 100ths, which, divided by 100, as before, will be the in terest required. To halve any thing, we divide by 2. Note. It will be recollected, that, to divide a fraction by 2, we can 1. What is the interest of $60 for 15 days? $60 1 Ans. $,15. 2. What is the interest of $24 for 10 days? 10 days = $24 mo.= 2, multiplier. 3. What is the interest of $120,60 for 20 days? Ans. $,04. $120,60 1348 Ans. $,4020. 4. What is the interest of $360,60 for 19 days? $360,60 12 Ans. $1,14,1 m. Hence, to find the interest of any sum for days, we have the following RULE. Q. How do you proceed first? A. I find what fractional part of a month the days are, and reduce the fraction to its lowest terms. Q. What do you make the multiplier ? Q. How do you halve the fraction? A. Halve the numerator, or double the denominator. Q. After you have multiplied by the fraction, what is to be done with the product, to get the interest? A. Cut off two figures, as before. Mental Exercises. 1. What is the interest of $120 for 15 days? A. 30 cts. 2. Interest of $60 for 15 days? A. 15 cts. A. 10 cts. 3. Interest of $18 for 20 da.? A. 6 cts. A. 3 cts. 4. Interest of $120 for 1 da.? A. 2 cts. A. 4 cts. For 10 da.? For 10 da.? For 2 da.? 5. Interest of $60 for 3 da.? A. 3 cts. For 6 da.? A. 6 cts. Exercises for the Slate. 1. What is the interest of $1200 for 2 da.? 2. What is the interest of $600 for 20 da.? $1200 30 Ans. 40 cts. $600 डै Ans. $2,00 A. $6. 3. What is the interest of $2400 for 15 da.? 4. What is the interest of $3600 for 10 da.? 5. What is the interest of $726 for 20 da.? 6. What is the interest of $1200 for 1 da. ?-20. 60. For 4 da. ?-80. For 5 da. ?-1. For 10 da. ?-2. 3. For 20 da. ?-4. For 25 da. ?-5. A. $16,60. For 3 da. For 15 da. ? 7. What is the interest of $120 for 8 yrs. 4 mo. 15 da. ? $120 8 yrs. 4 mo.=100÷2=50; and 15 da. mo.-2; then then, 501 8. What is the interest of $1200,60 for 1 yr. 10 mo. 24 da.? 1 yr. 10 mo.=22÷2=11 mo. ;, and 24 da. }& = 1. 6000 30 Ans: $60,30 $1200,60 11 1320660 Note. When the days are an even number, it will oftentimes be found convenient to find what fractional part of a month half the days will be, without halving the fraction afterwards; thus, for 20 days, take 10 days=8, the multiplier. 9. What is the interest of $180 för 29 days? A. 87 cts. 10. What is the amount of $180,60 for 2 yrs. 4 mo. 20 da.? A. $206,486. 11. What is the amount of $36,60 for 2 yrs. 1 mo. 5 da.? A. $41,205. 12. What is the interest of $300 for 1 yr. 6 mo. 15 da. ?— 2775. For 2 yrs. 6 mo. 15 da. ?-4575. For 3 yrs, 4 mo. 10 da. ?~ 6050. For 4 yrs. 4 mo. 5 da. ?-7825. A. $212,25. 13. What is the interest of $600,50 for 2 yrs. ?-7206. For 1 yr. 8 mo. ?-6005. For 2 yrs. 8 mo. 1 da. ?-9618. For 5 yrs. 7 mo. 12 da. ?-202368. For 8 4 da. ?-30065. yrs. 4 mo. A: $731,308. 14. What is the interest of $700 for 1 yr. ?-42. For 6 mo. ?2275. For 4 mo. ?-14. For 20 da. ?-2333. A. $81,083. 15. What is the amount of $60000 for 3 da. ?-60030. For 8 da. ?-60080. For 9 da. ?-60090. A. $180200.. 16. What is the interest of $60 for 2 mo. I da.?-61. For 2 mo. 2 da. ?-62. For 2 mo. 3 da. ?-63. A. $1,86. 17. What is the interest of $60 for 2 mo. 7 da. ?-67. For 2 mo. 8 da. ?-68. For 2 mo. 12 da. ?-72. A. $2,07. 18. What is the interest of $1200 for 12 yrs. 11 mo. 29 da.? A. $935,80. The foregoing example, although it is as difficult a one as usually occurs, is solved by one third of the usual number of figures required by other methods. 1 LXIII. cent. ; thus, 5 per It is evident, that, when the rate is either more or les than 6 per cent., the interest for the given rate will be a certain part of 6 per cent. will be as much as 6 per cent., 4 per cent. as much, &c. much, 7 per cent. To get of any number, we multiply by the numerator, and divide by the denominator; and, as the denominator will always be 6, and the numerator the given rato, hence, To find the interest of any sum, when the rate is not 6 per cent., we have the following Q. How do you proceed? RULE. A. Find the interest for 6 per cent. as before. Q. How do you proceed next? A. Multiply the interest of 6 per cent. by the given rate, and always divide by 6. 1. What is the interest of $600 for 1 yr. 2 mo. and 15 days, at 5 per cent.? 600 7 mo. 4200 150 4350 int. at 6 per cent. 6)21750 Ans. $ 36,25 int. at 5 per cent. 2. What is the interest of $240 for 2 yrs. mo. at 1 per cent. ?6. At 2 per cent. ?-12. At 4 per cent. ?-24. At 6 per cent. ?36. At 10 per cent. ?-60. At 5 per cent. ?-33. A. $171. 3. What is the interest of $480 for 3 yrs. 2 mo., at 15 per cent. ?-228. At 20 per cent. ?-304. At 10 per cent. ?-16340. At 15 per cent. ?-23560. At 7 per cent. ?-10640. A. $1037,40. 4. What is the interest of $600 for 15 mo., at 23 per cent. ?20625. At 3 per cent. ?-28125. A. $48,75. 5. What is the interest of $600 from January 1st to March 1st?-6. From January 15th to May 15th ?-12. From January 15th to September 15th ?-24. A. $42. 6. What is the amount of $500 from March 10th, 1824, to March 10th, 1827?-590. From March 29th, 1820, to March 29th, 1826?-680. From March 16th, 1820, to March 16th, 1824 ?620. A. $1890. 7. What is the interest of $60 from June 1st, 1826, to November 1st, 1827?-510. From April 1st, 1825, to August 16th, 1826-495. From July 4th, 1825, to August 19th, 1828?-1125, A. $21,30. 8. What is the interest of $300 from September 5th, 1825, to September 25th, 1826?-1. From August 9th, 1826, to Decem ber 24th, 1827 ?-2475. A. $25,75. 9. What is the amount of $180 from October 1st, 1826, to December 1st, 1830? A. $225. 1 LXIV. A concise and practical Rule for the State of New York, in which the interest is established by law at 7 per cent. It has been remarked, that 7 per cent. is of 6 per cent.; that is, more than 6 per cent.: hence, Q. To find the interest at 7 per cent., what is the A. Add RULE ? of the interest, at 6 per cent. (found as before), to itself; the sum will be the interest at 7 per cent. Note. The intorest for any rate per cent. may be found in the same manner, by subtracting, when the given rate is under 6 per cent., and adding, when it is more. 1. What is the interest of $360 for 20 days, at 7 per cent.? 2. What is the interest of $60 for 2 yrs. 4 mo., at 7 per cent.? A. $9,80. 3. What is the amount of $120,60 for 1 yr. 6 mo. 10 da., at 7 per cent.? A. $133,497 m. |