Let us suppose the sum lent, or due, to be $1. The 100th part of $1, or do of a dollar, is 1 cent, and 8 of a dollar, the legal interest, is 6 cents, which, written as a decimal fraction, is expressed thus, So of any other rate per cent. 1 per cent., expressed as a common fraction, is Too; decimally, per cent. is a half of 1 per cent., that is, '06. '01. '005. '0075. Note. The rate per cent. is a decimal carried to two places, that is, to hundredths; all decimal expressions lower than hundredths are parts of 1 per cent. per cent., for instance, is '625 of 1 per cent., that is, '00625. 1. If the interest on $1, for 1 year, be 6 cents, what will be the interest on $17 for the same time? It will be 17 times 6 cents, or 6 times 17, which is the same thing: $17 1 '06 1'02 Answer; that is, 1 dollar and 2 cents. To find the interest on any sum for 1 year, it is evident we need only to multiply it by the rate per cent. written as a decimal fraction. The product, observing to place the point es directed in multiplication of decimal fractions, will be the interest required. Note. PRINCIPAL is the money due, for which interest is paid. AMOUNT is the principal and interest added together. 2. What will be the interest of $32'15, 1 year, at 41 per eent.? dollar, 44 cents, 6 mills, and not generally regarded; hence, for the answer. There being five decimal places in the multiplicand and multiplier, five figures must be pointed off for decimals from the product, which gives the answer,-1 of a mill. Parts of a mill are $1'446 is sufficiently exact 8. What will be the interest of $11'04 for 1 year, at 3 per cent. ? at 51 per cent. ? at 6 per cent. ? at 74 per cent.? per cent.? at 112 per cent. ? at 12 per cent. ?. at 12 per cent. ? 4. A tax on a certain town is $1627'18, on which the collector is to receive 24 per cent. for collecting; what will he receive for collecting the whole tax at that rate? Ans. $40'679. Note. In the same way are calculated commission, insurance, buying and selling stocks, loss and gain, or any thing else rated at so much per cent. without respect to time. 5. What must a man, paying $0'37 on a dollar, pay on a debt of $ 132′25 ? Ans. $49'593. 6. A merchant, having purchased goods to the amount of $580, sold them so as to gain 12 per cent., that is, 12 cents on each 100 cents, and in the same proportion for a greater or less sum; what was his whole gain, and what was the whole amount for which he sold the goods? Ans. His whole gain was $72'50; whole amount $652'50. 7. A merchant bought a quantity of goods for $763'37; how much must he sell them for to gain 15 per cent. ? Ans. $ 877'881. T82. COMMISSION is an allowance of so much per cent. to a person called a correspondent, factor, or broker, for assisting merchants and others in purchasing and selling goods. 8. My correspondent sends me word that he has purchased goods to the value of $1286, on my account; what will his commission come to at 24 per cent.? Ans. $32'15. 9. What must I allow my correspondent for selling goods ⚫ to the amount of $2317'46, at a commission of 31 per cent.? Ans. $75'317. INSURANCE is an exemption from hazard, obtained by the payment of a certain sum, which is generally so much per cent. on the estimated value of the property insured. PREMIUM is the sum paid by the insured for the insurance. POLICY is the name given to the instrument or writing, by which the contract of indemnity is effected between the insurer and insured. 10. What will be the premium for insuring a ship and cargo from Boston to Amsterdam, valued at $37800, at 43 per cent. ? Ans. $1701. 11. What will be the annual premium for insurance on a house against loss from fire, valued at $3500, at 2 per cent.? By removing the separatrix 2 figures towards the left, it is evident, the sum itself may be made to express the premium at 1 per cent., of which the given rate parts may be taken; thus, 1 per cent. on $3500 is $35'00, and of $35.00 is $26'25, Answer. 12. What will be the premium for insurance on a ship and cargo valued at $25156'86, at per cent.? cent.? per cent. ? at per at at per cent. ? at per cent? STOCK is a general name for the capital of any trading company or corporation, or of a fund established by govern ment. The value of stock is variable. When 100 dollars of stock sells for 100 dollars in money, the stock is said to be at par, which is a Latin word signifying equal; when for more, it is said to be above par; when for less, it is said to be below par. 13. What is the value of $7564 of stock, at 1124 per cent.? that is, when 1 dollar of stock sells for 1 dollar 121 cents in money, which is 123 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 951 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 861 per cent. ? at 672 per cent.? per cent.? at 1081 per cent. ? at 37 per cent. advance? at 104+ at 115 per cent. ? LOSS AND GAIN. 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.? T 83. We have seen how interest is cast on any sum of money, when the time is one year; but it is frequently ne cessary 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, '005 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 (3 times 6 =18) days, will be '008, which, united with the cents, ('048,) give 4 cents 8 mills for the interest of $1 for months and 18 days. 1. What will be the interest on $1 for 5 months 6 days? 6 months 12 days? 7 months? 9 months 12 days? 24 days? 8 months 15 10 months? 12 months 18 days? 16 months? ODD 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. of a mill. 3. What will be the interest of $1 for 1 month 8 days? 2 months 7 days? months 22 days? 17 days? 3 months 15 days? 5 months 11 days? 7 months 3 days? 9 months-2 days? 11 months 4 days? 4 6 months 8 months 11 days? 10 months 15 days? 12 months 3 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 months 1 day? 4. What will be the interest of $1 for 2 4 months 2 days? months 4 days? for 1 day? for 5 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 '0408 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 oice for every 6 days, for 3 days take, for 2 days take 0.* |