cents in money, which is 124 per cent. above par, or 121 per cent. advance, as it is sometimes called. Ans. $8509'50. 14. What is the value of $3700 of bank stock, at 954 per cent., that is, 44 per cent. below par? Ans. $3533'50. 15. What is the value of $120 of stock, at 921 per cent. ? at 86 per cent.? at 67 per cent. ? at 1081 per cent.? at 37 per cent. advance? per cent.? Loss AND GAIN. at 104 at 115 per cent. ? 16. Bought a hogshead of molasses for $60; for how much must I sell it to gain 20 per cent. ? Ans. $72. 17. Bought broadcloth at $2'50 per yard; but, it being damaged, I am willing to sell it so as to lose 12 per cent.; how much will it be per yard? Ans. $2'20. 18. Bought calico at 20 cents per yard; how must I sell it to gain 5 per cent.? 10 per cent. ? 15 per cent.? Ans. to the last, 16 cents per yard. to lose 20 per cent.? ¶ 83. We have seen how interest is cast on any sum of money, when the time is one year; but it is frequently necessary to cast interest for months and days. Now, the interest on $1 for 1 year, at 6 per cent., being '06, is '01 cent for 2 months, 'G05 mills (or a cent) for 1 month of 30 days, (for so we reckon a month in casting interest,) and '001 mill for every 6 days; 6 being contained 5 times in 30. Hence, it is very easy to find by inspection, that is, to cast in the mind, the interest on 1 dollar, at 6 per cent. for any given time. The cents, it is evident, will be equal to half the greatest even number of the months; the mills will be 5 for the odd month, if there be one, and 1 for every time 6 is contained in the given number of the days. Suppose the interest of $1, at 6 per cent., be required for 9 months, and 18 days. The greatest even number of the months is 8 half of which will be the cents, '04; the mills, reckoning 5 for the odd month, and 3 for the 18 (2 times 6) 18) days, will be '008, which, united with the cents, ('048,) give 4 cents 8 mills for the interest of $1 for 9 months and 18 days. 9 months 12 days? 1. What will be the interest on $1 for 5 months 6 days? 6 months 12 days? 24 days? 10 months? 11 months 6 days? months 6 days? 12 months 18 days? 15 16 months? ÖDD DAYS. 2. What is the interest of $1 for 13 months 16 days? The cents will be 6, and the mills 5, for the odd month, and 2 for 2 times 6 12 days, and there is a remainder of 4 days, the interest for which will be such part of 1 mill as 4 days is part of 6 days, that is, of a mill. Ans. ‘0673. = 3. What will be the interest of $1 for 1 month 8 days? 3 months 15 days? 2 months 7 days? months 22 days? 17 days? 5 months 11 days? 6 months 8 months 11 days? 10 months 15 days? 12 months 3 days? 7 months 3 days? 9 months 2 days? 11 months 4 days? Note. If there is no odd month, and the number of days be Less than 6, so that there are no mills, it is evident, a cipher must be put in the place of mills; thus, in the last example,-12 months 3 days,-the cents will be '06, the mills 0, the 3 days a mill. Ans. '060 4. What will be the interest of $1 for 2 months 1 day? 4 months 2 days? months 4 days? for 1 day? for 5 days? 6 months 3 10 months 5 days? for 2 days? 5. What is the interest of $ 56'13 for 8 months 5 days? The interest of $1, for the given time, is '040; therefore, ) and ) $56'13 principal. 5 days '040% interest of $1 for the given time. 224520 interest for 8 months. 2806 interest for 3 days. 2'29197, Ans. $2'291. 3 days + 2 days. As the multiplicand is taken once for every 6 days, for 3 days take, for 2 days take, ** I of the multiplicand. += . So also, if the odd days be 42 days+2 days, take of the multiplicand twice; for 1 day, take f Note. If the sum on which interest is to be cast be less than $10, the interest, for any number of days less than 6, will be less than 1 cent; consequently, in business, if the sum be less than $10, such days need not be regarded. From the illustrations now given, it is evident,-To find the interest of any sum in federal money, at 6 per cent., it is only necessary to multiply the principal by the interest of $1 for the given time, found as above directed, and written as a decimal fraction, remembering to point off as many places for decimals in the product as there are decimal places in both the factors counted together. EXAMPLES FOR PRACTICE. 6. What is the interest of $87'19 for 1 year 3 months? 7. Interest of $116,08 for 11 mo. 19 days? of $8'50 for 1 year 9 mo. 12 days? of $073 for 10 mo. ? Note. The interest of $1 for 6 days (being 1 mill, the dolDess themselves ex press the interest in mills for six days, of which we may take parts. Thus, 6) 15000 mill 2'500, that is, $250, Ans. to the last. When the interest is required for a large number of years, it will be more convenient to find the interest for one year, and multiply it by the number of years; after which find the interest for the months and days, if any, as usual. 18. What is the interest of $1000 for 120 years? Ans. $7200 19. What is the interest of $520'04 for 30 years and months? Ans. $951'673. 89, 84. INTEREST. 163 20. What is the interest on $400 for 10 years 3 months and 6 days? 50 years? Ans. $246'40. for 21. What is the interest of $220 for 5 years? 12 years? Ans. to last, $660. 22. What is the amount of $86, at interest 7 years? Ans. $122'12. 23. What is the interest of 36 £. 9 s. 64 d. for 1 year? Reduce the shillings, pence, &c. to the decimal of a pound, by inspection, (T76;) then proceed in all respects as in federal money. Having found the interest, reverse the operation, and reduce the three first decimals to shillings, &c., by inspection. (T 77.) Ans. 2 £. 3 s. 9 d. 24. Interest of 36 £. 10 s. for 18 mo. 20 days? Ans. 3 £. 8 s. 1 d. Interest of 95 £. for 9 mo.? Ans. 4 £. 5 s. 6 d. 25. What is the amount of 18 £ 2 s. at interest 10 months 3 days? Pearlere Ans. 19 £. 10 s. 94 d. 26. What is the amount of 100 £. for 8 years? Ans. 148 £. 27. What is the amount of 400 £. 10 s. for 18 months? Ans. 436 £. 10 s. 10 d. 3 q. 28. What is the amount of 640 £. 8 s. at interest for 1 for 2 years 6 months? for 10 years? Ans. to last, 1024 £. 12 s. 91 d. year? 184. 1. What is the interest of 36 dollars for 8 months, at 41 per cent.? first Note. When the rate is any other than six per cent., find the interest at 6 per cent., then divide the interest so found by such part as the interest, at the rate required, exceeds or falls short of the interest at 6 per cent., and the quotient added to, or subtracted from the interest at 6 per cent., as the case may be, will give the interest at the rate required. $36 '04 2)144 $36 1'08 Ans. 4 per cent. is of 6 per cent.; therefore, from the interest at 6 per cent. subtract ; the remainder will be the interest at 44 per cent. 2. Interest of $54'81 for 18 mo., at 5 per ct.? Ans. $4'11. 3. ........... of $500 for 9 mo. 9 days, at 8 per ct.? $31'00 4. ........... of $62'12 for 1 mo. 20 days, at 4 per ct.? $345 5. Interest of $ 85 for 10 mo. 15 days, at 124 per cent.? Ans. $9'295 6. What is the amount of $53 at 10 per ct. for 7 mo. ? Ans. $56'091. The time, rate per cent. and amount given, to find the principal. ¶ 85. 1. What sum of money, put at interest at 6 per cent., will amount to $61'02, in 1 year 4 months? The amount of $1, at the given rate and time, is $ 1'08; hence, $61'02 $1'08 = 56'50, the principal required; that is, Find the amount of $1 at the given rate and time, by which divide the given amount; the quotient will be the principal required. Ans. $56'50. 2. What principal, at 8 per cent., in 1 year 6 months, will amount to $85′12? Ans. $76. 3. What principal, at 6 per cent., in 11 months 9 days, will amount to $99'311? Note. The interest of $1, for the given time, is '0561; but, in these cases, when there are odd days, instead of writing the parts of a mill as a common fraction, it will be more convenient to write them as a decimal, thus, '0565; that is, extend the decimal to four places. Ans. $94. 4. Á factor receives $988 to lay out after deducting his commission of 4 per cent.; how much will remain to be laid out? It is evident, he ought not to receive commission on his own money. This question, therefore, in principle, does not differ from the preceding. Note. In questions like this, where no respect is had to time, (T 81, ex. 4, note,) add the rate to $1. Ans. $950. 5. A factor receives $1008 to lay out after deducting his commission of 5 per cent.; what does his commission amount to? Ans. $48. DISCOUNT. 6. Suppose I owe a man $397'50, to be paid in 1 year, without interest, and I wish to pay him now; how much ought I to pay him when the usual rate is 6 per cent. ? I ought to pay him such a sum as, put at interest, would, in 1 year, amount to $397'50. The question, therefore, does not differ from the preceding. Ans. $375. Note. An allowance made for the payment of any sum |