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 $ 2317646, at a commission of 34 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 4 per cent. ? Ans. $1701. 11. What will be the annual premium for insurance on a house against loss from fire, valued at $3500, at & per cent. ? By removing the separatrix 2 figues towards the left, it is evident, the sum itself may be made 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. - at per 12. What will be the premium for insurance on a ship and cargo valued at $25156'86, at + per cent. ? cent.? at & per cent.? - at per cent? per cent. ? Ans. At per cent. the premiun is $ 157'23. at 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 12+ 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 95 per cent., that is, 42 per cent. below par? Ans. $3533'50. 15. What is the value of $ 120 of stock, at 924 per cent.? at 864 per cent. ? at 67 per cent. ? at 104 per cent.? at 1084 per cent.? - at 115 per cent. ? at 37 per cent. advance? 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 $2650 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. $220. 18. Bought calico at 20 cents per yard; how must I sell it *o gain 5 per cent.? - 10 per cent. ? 15 per cent. --to lose 20 per cent.? Ans. to the last, 16 cents per ya. 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 9 months and 18 days. 1. What will be the interest on $1 for 5 months 6 days? 6 months 12 days? - 7 months? 8 months 10 months? 24 days? - - 9 months 12 days? 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. 3. What will be the interest of $1 for 1 month 8 days? 4 2 months 7 days? - 3 months 15 days? months 22 days? - 5 months 11 days? - 6 mouths 17 days? 7 months 3 days? - 8 months 11 days? - 9 months 2 days? 10 months 15 days? 11 months 4 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 r ust 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. '0604. 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 days? 10 months 5 days? for 3 days? for 4 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, 2) and $) $ 56'13 principal. '040 interest of $1 for the given time. 224520 interest for 8 months. 2806 interest for 3 days. 2629197, Ans. $26291. 5 days = 3 days + 2 days. As the multiplicand is taken once for every 6 days, for 3 days take, for 2 days take +, 0* of the multiplicand. + + + = &. So also, if the odd days be 4 = 2 days + 2 days, take of the multiplicand twice; for 1 day, take t. Note. It the sun on which interest is to be rast 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 vear 3 months? Ans. $6'539. 7. Interest of $ 116,08 for 11 mo. 19 days? $66751. of $8'50 for 1 year 9 mo. 12 days? $6909. of $675 for 1 mo. 21 days? $56737 of $ 73'50 for 2 days ? rest of $1 for 6 days ........... of $ 180'75 for 5 days? (being 1 mill, the dol .... of $15000 for 1 day? lars themselves ex press the interest in mills for six days, of which we may take parts. Thus, 6) 15000 mills, 2'500, that is, $ 2'50, 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 fina 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 6 mouths! Ans. $951'673. 20. What is the interest on $ 400 for 10 years 3 months and 6 days? Ans. $246'40. 21. What is the interest of $220 for 5 years? 12 years? - 50 years? 22. What is the amount of $86, at interest 7 years? for Ans. to last, $660. Ans. $122-12 23. What is the interest of 36 £. 9 s. 6 d. for 1 year? Reduce the shillings, pence, &c. to the decimal of a pound, by inspection, (1 76;) 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. (177.) Ans. 2 £. 3 s. 9 d. 24. Interest of 36 £. 10 s. for 18 mo. 20 days? Ans. 3 £. 8 s. 14 d. Interest of 95 £. for 9 mo. ? Ans. 4 £.5 s. 6 d 25. What is the amount of 18 £. 12 s. at interest 10 months 3 days? Ans. 19 £. 10 s. 91 d. 26. WLat 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 £.8s. at interest for 1 year? for 2 years 6 months? for 10 years? Ans. to last, 1024 £. 12 s. 9 d. 84. 1. What is the interest of 36 dollars for 8 months, at 4 per cent. ? Note. When the rate is any other than six per cent., first 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 1)144 '36 1'08 Ans. 44 per cent. is of 6 per cent.; therefore, from the interest at 6 per cent. subtract + the remainder will be the interest at 41 per cent. 2. Interest of $ 54'81 for 18 mo., at 5 per ct.? Ans. $4'11. 3. 4. .......... of $ 500 for 9 mo. 9 days, at 8 per ct.? $31.00. ........... of $ 62'12 for 1 mo. 20 days, at 4 per ct. ? $345. |