« ΠροηγούμενηΣυνέχεια »
that will allow each owner to lay out all his land. How many rods must there be in a lot?
PROBLEM X. Two or more numbers being given, to find their least common multiple; that is, the least number that will contain each of the given numbers a whole number of times. RULE. Divide two or more of the given numbers by any prime number that will measure them, repeat the operation upon the quotients and undivided numbers, and thus continue, till they become prime to each other. Multiply the several divisors, the last quotients, and undivided numbers together; the product will be the least common multiple.
If, among the numbers to be divided, any number is a measure of another, the measuring number may be rejected; that is, dropped from the operation.
It is obvious, that one number is the multiple of another, when the former contains all the factors of the latter. The factors of 6 are 3 and 2, and the factors of 9 are 3 and 3. Now 54 contains all these factors, (3 X2 X3X 3=54), and 54 is a common multiple of 6 and 9, but it is not their least common multiple—it is 3 times as great as the least, owing to the existence of the factor, 3, in both 6 and 9. Hence we observe, that a common. factor of two or more numbers must enter but once into the multiplication, to give the least common multiple. The above rule effects the
exclusion. 23. What is the least common multiple of 12, 25, 30, and 45.
3) 12 25 30 45 We find, after dividing 5) 4 25
twice, that 4 and 2 ap
pear; and, by dropping 4 5 2 3 the 2 because it measures
the 4, we avoid another 3 X5 X4 X5 X3=900 division. Ans. 900.
24. What is the least common multiple of 6, 10, 16, and 20 ?
25. What is the least common multiple of 25, 35, 60, and 72 ?
26. What is the least common multiple of 105, 140, and 245 ?
27. What is the least common multiple of 13, 82, 94, 789, and 356 ?
28. Allowing 63 gallons to fill a hogshead, 42 a tierce, and 32 a barrel, what is the smallest quantity of mulasses, that can be first shipped in some number of full housheads, then discharged and reshipped in some number of full tierces, and again discharged and reshipped in some number of full barrels ?
29. A certain four dealer, who purchased his four from a mill on the opposite side of a river, owned four boats, one of which would carry 8 barrels of four, another 9, another 15, and another 16. What is the smallest number of barrels he could purchase, that would make some number of full freights for either of the boats ?
COMPOUND NUMBERS are those which are employed to express quantities that consist of several denon inations; each denomination being denoted separately. Under this head are classed, all the subdivisions of measures; of length, surface, solidity, weights, money, time, &c.
The following tables of denominations of compound numbers, show how many units of each lower denomination are equal to a unit of the next higher, anı, exhibit each lower denomination as a fraction of the next higlier.
MONEY, WEIGHTS, AND MEASURES.
ENGLISH MONEY. The denominations of English Money are, the pound, £, the shilling, 8., the penny, d., and the farthing, gr. 4 farthings
of id. 1 s.
12 20 shillings
of I s.
as of 1 £.
=tof 1 lb.
of 1 qr.
TROY WEIGHT. The denominations of Troy Weight are, the pound, ib., the ounce, oz., the pennyweight, dwt., and the grain, gr. 24 grains ...
i dwt.|| 1gr.
za nf i dwt 20 pennyweights
Zo of 1oz. 12 ounces
1 oz. Iz of ilb. AVOIRDUPOIS WEIGHT. The denominations of Avoirdupois Weight are, the ton, T., the hundred-weight, cwt., the quarter, gr. the pound, 16., the ounce, oz.,
and the dram, dr. 16 drams
1 of 1 oz. 16 ounces
1 oz. 28 pounds
of 1 cwt. 20 hundred-weight
of 1 T. APOTHECARIES' weight. The denominations of Apothecaries' Weight are, the pound, tb, the ounce, 3, the dram, 3, the scruple, , and the grain, gr. 20 grains 19.
of 1. 3 scruples :13. 12
1 of 13. 8 drams . 13. 13
Š of 13. 12 ounces
of 1 lb. CLOTH MEASURE. The denominations of Cloth Measure are, the French ell, Fr. e., the English ell, E. e., the Flemish ell, Fl.e., the yard, yd., the quarter, qr., and the nail, na. 4 nails =1 qr
qr. 4 quarters
lyd. 1 qr. of 1 yd 3 quarters
1 Fl.e. 1 qr.
of 1 Fl. e. 5 quarters 1 E. e. I qr.
of 1 E. e. 5 quarters 1 Fr.e.l 1qr.
of i Fr. e.. DRY MEASURE. The denominations of Dry Measure are, the bushel, bu., the peck, pk., the gallon, gal., the quart, qt., and the pint, pt. 2 pints
of iqt; 4 quarts
1 gal | 1qt.
of 1 gal. 8 quarts 1 pk. || 1qt.
of 1 pk. 1 bu. I 1pk.
of 1 bu.
of 1 pt. of 1qt.
1 gal. 1 gal. 1 gal.
WINE MEASURE. The denominations of Wine Measure are, the tun, T., the pipe, p., the puncheon, pun., the hogshead, hhd., the tierce, tier., the barrel, bl., the gallon, gal., the quart, gt. the pint, pt. and the gill, gi. 4 gills
1 pt. 2 pints
1qt. 1 pt. 4 quarts
of i gal. 31į gallons 1 bl.'
of 1 bl. 42 gallons
of 1 tier. 63 gallons 1 hhd.
1 of i hhd, 84 gallons
84 pun. 126 gallons
p. 1 gal. IÀg of 1p. 2 pipes =1T.
of 1 T. BEER MEASURE. The denominations of Beer Measure are, the butt, bt , the hogshead, hhd., the barrel, bl., the kilderkin, kil., the firkin, fir., the gallon, gal., the quart, qt., and the pint, pt. 2 pints 4 quarts
of 1 gal. 9 gallons
of 1 fir. 2 firkins
of 1 kil. 2 kilderkins 1 bl. 1 k:1.
of 1 ul. 3 kilderkins 1 hhd. 1 kil.
of 1 hhd. 2 hogsheads I bt. 1 hhd.
of 1 bt.
of 1 qt.
In the United States, the Dry gallon contains 2685 cubic inches, the Wine gallon 231 cubic inches, and the Beer gallon 282 cubic inches. By an Act of the British government, however, the distinction between the Dry, Wine, and Beer gallon was abolished in Great Britain, in 1826, and an Imperial Gallon was established, as well for liquids as for dry substances. The Imperial gallon must contain “10 pounds, Avoirdupois weight, of distilled water, weighed in air, at the temperature of 62° of Fahrenheit's thermometer, the barometer standing at 30 inches.” This quantity of water will be found to measure 2771000
274 cubic inches. The same Act establishes the pound Troy at 5760 grains, and the pound Avoirdupois at 7000 grains
of lyd. of Ir.
LONG MEASURE. The denominations of Long Measure are, the nile, m., the furlong, fur., the rod or pole, r., the yard, yd., the fooi, fl., and the inch, in. 12 inches
I ft. lin.
i's of ifi. 3 feet
lyd. 1 ft. 5 yards
Ir. I yd. 40 rods.
of i fur. 8 furlongs
I fur. À of im.
SQUARE MEASURE. The superficial contents of any figure having four sides and four equal angles, is found in squares, by multiplying together the length and breadth of the figure.
Tue denoininations of Square Measure are, the mile, m., the acre, A., the rood, R., the red, r., the yard, yd., the foot, fl., and the inch, in. 144 inches
I ft. 1 in. 117 of 1 ft. lyd. 1 ft.
of' lyd. 30 yards . .
Ir. 1 yd.
121 * 40 rods
of i R. 4 roods TA. IR.
of 1A. 640 acres
CUBIC MEASURE. The cubical contents of any thing which has 6 sides, its opposite sides being equal --- is found in cubes, by multiplying together, the length, breadth and depth.
The denominations of Cubic Measure are, the yard, yd., the foot, fl., and the inch, in. 1728 inches
of 1 ft. 27 feet
lyd. ll Ift.
27 40 feet of round timber, or 50 feet of bewn timber make a ton. 16 cubic feet make a foot of wood, and 3 feet of wood make a cord.
9 feet . . .
of 1 m.
The denominations of Time are, the year, Y., the day, d., the hour, h., the minute, m., and the second, s. 60 seconds =lm.
do of 1 in. 60 minutes
of 1 h. 24 tours
1 of 1 d.