Hence, to find the interest of any sum for days, we have the following RULE. I. 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. II. What do you make the multiplier? A. Half of this fraction. III. How do you halve the fraction? A. Halve the numerator, or double the denominator. IV. 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. 10 cts. 3. Interest of $18 for 20 da.? A. 6 cts. 4. Interest of $120 for 1 da.? A. 2 cts. 5. Interest of $60 for 3 da.? A. 3 cts. For 10 da.? A. For 10 da.? A. 3 cts. For 2 da.? A. 4 cts. A. 6 cts. $1200 Exercises for the Slate. 1. What is the interest of $1200 for 2 da. ? 2 days÷2= =36, multiplier 2. What is the interest of $600 for 20 da? 20 days=38÷2=}, multiplier A. $6. 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) For 3 da.? (60) For 4 da.? (80) For 5 da.? (1) For 10 da.? (2) For 15 da.? (3) For 20 da.? (4) For 25 da.? (5). A. $16,60. 7. What is the interest of $120 for 8 yrs. 4 mo. .15 da.? $120 8 yrs. 4 mo. 100÷250; aná 15 da == the multiplier for the days and months is 50₫. mo.÷2; then, 50+ 6090 30 Ans. $60,30 8. What is the interest of $1200,60 for 1 yr.. 10 mo. 24 da. ? .r. 10 mo. 22÷2=11 mo. ; and 24 da. 2=; the multiplier, then, is 114. $1200.60 11 1320660 48024 Ans. $136,8680 m. 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 = 18 = 1, the multiplier. 9. What is the interest of $180 for 29 days? A. 87 cts. 10. What is the amount of $180,60 for 2 yrs. 4 mo. 20 da.? 4. $206,486. I. 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 yrs. 4 mo. 4 da. ? (30065) 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. 1 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 ¶ LXIII. It is evident, that, when the rate is either more or less than 6 per cent., the interest for the given rate will be a certain part of 6 per cent.; thus, 5 per cent. will be as much as 6 per cent., 4 per cent. 告 as much, 7 per cent. as much, &c. 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 rate, hence, To find the interest of any sum, when the rate is not 6 per cent., we have the following RULE. I. How do you proceed? A. Find the interest for 6 per cent. as before. II. 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 74 mo. 4200 150 4350 int. at 6 per cent 5 6)21750 Ans. $36,25 int. at 5 per cent 2. What is the interest of $240 for 2 yrs. 6 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) $1037,40. Á. 4. What is the interest of $600 for 15 mo., at 23 per cent.? (20625) At 34 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, 1826, to September 25th, 1826? (1) From August 9th, 1826, to December 24th, 1827? (2475) A. $25,75. 9. What is the amount of $180 from October 1st, 1826, to December 1st, 1830? A. $225. ¶ 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 RULE? A. Add of the interest, at 6 per cent. (found as before), to itself; the sum will be the interest at 7 per cent. Note. The interest 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. 4. What is the amount of $241,20 for 6 mo. 20 da.? (25058) For 1 mo. 1 da.? (242653) For 1 yr. 4 mo. 5 da.? (263946) For yrs. 6 mo. 25 da.? (284582) A. $1041,761+. 2 ¶ LXV. Since 6 per cent. is $6 on $100, that is, Tʊ of the principal, and 5 per cent. To, &c., hence, To calculate the interest at any rate per cent., when the time is 1 year, we proceed as follows: RULE. Multiply by the given rate, and cut off two figures, as before. 1. What is the interest of $220,40 for 1 yr., at 9 per cent? $ 220,40 9 $19,8360 Ans. 2. What is the interest of $1200,30 for 1 yr., at 12 per cent.? A. $150,03,7. 3. What is the amount of $80,10, for 1 yr., at 2 per cent.? (82102) At 5 per cent.? (84105) At 10 per cent.? (8811) At 4 per cent.? (83704) At 19 per cent.? (95919) A. $433,94+ ¶ LXVI. COMMISSION. Q. When an allowance of so much per cent. is made to a person called either a correspondent, factor, or broker, for buying, or assisting in buying and selling goods for his employer, what is it called? A. Commission. RULE. Since commission, insurance, buying and selling stocks, and loss and gain, are rated at so much per cent., without regard to time, how may all these be calculated? A. Multiply by the rate per cent., and cut off two figures, as in the last rule. 1. What would you demand for selling $400 worth of cotton, for 2 per cent. commission? $400 X 2, and cutting off two figures, = $10, commission, Ans. 2. My correspondent informs me that he has purchased goods to the amount of $5000; what will his commission amount to, at 2 per cent.? A. $125. 3. What must I be allowed for selling 300 pounds of indigo, at $2,50 per lb., for 2 per cent. commission? (15) For 2 per cent.? (20625) For 5 per cent.? (3750) For 6 per cent.? (4875) For 7 per cent.? (5250). A. $174,375. INSURANCE. Q. What is the allowance of so much per cent. made to persons, to make good the losses sustained by fire, storms, &c. called? A. Insurance. Q. By what name is the instrument that binds the contracting parties called? A. Policy. Q. What is the sum paid for insurance called? A. Premium. 1. What will be the premium for insuring an East India ship, valued at $25000, at 15 per cent.? A. $3875. 2. What is the premium for insuring $2600, at 20 per cent.? (520) At 30 per cent.? (780) At 18 per cent.? (481) 26 per cent.? (689) A. $2470. STOCK. Q. What is the general name for all moneys invested in trading companies, or the funds of government, called? A. Stock. |