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FEDERAL MONEY. II. To find the interest of any number of cents for any number of days less than a month, at 6. per cent.
RULE. Multiply the cents by the number of dars, divide the product by 6, and point off
' two figures to the right, and all the figures at the left liand of the dash, will be the interest in mills, nearly.
Required the interest of 85 dollars, for 20 days. 8 cts.
Ans. 283 wbich is
28 cts. 3 mills. 2. What is the interest of 73 dollars 41 cents, or 7341 cents, for 27 days, at 6 per cent. ?
Ans. 350 mills, or 33 cts.
III. When the principal is given in pounds, shillings, &c.
New-England currency, to find the interest for any number of days, less than a month, in Federal Money.
RULE. Multiply the shillings in the principal by the number of days, and divide the product by 36, the quotient will be the interest in mills, for the given time, nearly, oinitting fractions.
Required the interest, in Federal Money, of 271. 158. for 27 days, at 6 per
s. s. Ans. 27 15 5555 X 27:-36-416 mills.=41cts. 6m.
IV. When the principai is given in Federal Money, and
you want the interest in shillings, pence, &c. NewEngland currency, for any nunber of days less than a month
RULE. Multiply the principal, in cents, by the number of days, and point off five figures to the right hand of the product which will give the interest for the given time, in shil lings and decimals of a shilling, very nearly.
A note for 65 dollars, 31 cents, has been on interest 25 days; how much is the interest thereof, in New-England currency ? $ cts.
s. d. grs. Ans. 65,31=6531X25=1,63275 =1 72 REMARKS.- In the above, and likewise in the preceding practical Rules, (page 127) the interest is confined at six
per cent. which admits of a variety of short methods of casting; and when the rate of interest is 7 per cent. as established in New York, &c. you may first cast the interest at 6 per cent. and add thereto one sixth of itself, and the sum will be the interest at 7 per cent. which per haps, many times, will be found more convenient than the general rule of casting interest.
Required the interest of 75l. for 5 months at 7 per cent.
7,5 for 1 month.
£. s. d.
cent. += 6 S
Ans. £2 3 9 for ditto at 7 per cent.
A SHORT METHOD FOR FINDING THE REBATE OF ANY
1. What is the rebate of 50 dollars for six months, at 6 per sent.
The interest of 50 dollars tor 6 inontis, is 1 50
Ans. Rebate, 81 46 2. What is the rebate of 150l. for 7 months, at 5 per: cent. ?
Oterest of 1501. for 7 months, is 4 7 6 interest of 41. 7s. 6d. for months, is 2 64
Ins. £4 4 11} nearly. By, the above Rule, those who use interest tables in their counting-houses, have only to deduct the interest of the interest, and the remainder is the discount.
A concise Rute to reduce the currencies of the different
States, where a dollar is an even number of shillings, to Federal Money.
RULE I. Bring the given sum into a decimal expression by inspection, (as in Problem l. page 87) then divide the whole by ,3 16 New-England and by 4 in New York currency, and the quotient will be dollars, cents, &c.
1. Reduce 541. 8s. 5 d. New-England currency, to Federal Monev.
93)54,415 decimally expressed.
Ans. $181,38 cts. 2. Reduce 7s. 113d. New-England currency, to Fede. ra. Monev.
7s. 114d.=£0,599 then, ,3),399
Ans. $1,33 3. Reduce 5131. 16s. 10d. New-York, &c. currency, to Federal Money.
4. Reduce 19s. 5. New-York, di. currer Federal Honey.
10,974 decimal of 198 5.
$2,45?15, 5. Reduce 641. New England currency, to Federal Money.
61000 decimal expression.
219,354 Ans. Note... By the foregoing rule you may carry on the decimal: to any degree of exactness; but in ordinary practice, the following Contruction may be useful.
RULE II. To the shillings container in the given sum, annex 8 times the given pence, increasing the product by 2: then livide the whole by the number of shillings colilaitied in a doilar, and the quotient will be cents.
EXAMPLES. 1. Redluce 455. 6. New-England currency, to Pede. ral Money.
6x8+2 50 to he annexed,
7,58. cents.= 90 ''Reiluce 1. 10s. 9d. New-York, &c. currency, to Federal Money.
9x8+2=4 to be annexcd. Then 8)5074
Or thus, 8)50,74
$ ots. Ans. 634 cents. 6.34
86,31.418 N. B. When there are no pence in the given <!!!!!, you mullst annex two cyphers to the shillings; thea divide as before, &c.
3. Reduce sl. 5s. New-England currency, to Federal mouce.
3!. 59. *652. Then 6)6500
s. 1083 cents.
SOME USEFUL RULES, FOR FINDING THE CONTENTS OF SUPERFICIES AND
SOLIDS. SECTION I. OF SUPERFICIES. The superficies or area of any plane surface, is composed or made up of squares, either greater or less, according to the different measures by which the dimensions of the figure are taken or measured :—and because 12 inches in length make 1 foot of long measure, there fore, 12x12=144, the square inches in a superficial foot, &c.
Arr. I. To find the area of a square having equal sides.
RULE. Multiply the side of the square into itself, and the product will be the area, or content.
1. How many square feet of boards are contained in the floor of a room which is 20 feet square
20x20=400 feet, the Answer. 2. Suppose a square lot of land measures 26 rods on each side, how many acres doth it contain ? NOTE.--160
rods make an acre. Therefore, 26x26=676 sq. rods, and 676-160=42,
36r. the Answer. ART. 2. To measure a parallelogram, or long square.
RULE. Multiply the length by the breadth, and the product will be the area, or superficial content.
1. A certain garden, in form of a long square, is 96 ft. ong, and 34 wide; how many square feet of ground are contained in it ! Ans. 96 x 54=5144 square feet.
2. A lot of land, in form of a long square, is 120 rods in length, and 60 rods wide; how many acres are in it?
120X60=7200 sqr. rods, then 200=45 acres. Ans.
3. If a board or plank be 21 feet long, and 18 inches droad; how many square feet are contained in it?
18 inches=1,5 feet, then 21x1,5=31,5 Ans.