Εικόνες σελίδας
PDF
Ηλεκτρ. έκδοση

ches at the bung diameter, is ordered to make another cast
of the same shape, but to hold just twice as much; wha
will be the bung diameter and length of the new cask ?
40 X 40 X 40 X 2=128000 then ✓ 128000=50,3+length.
B2x32x32x2=65536 and 765536=40,3+ bung diam.

3

3

A General Rule for extracting the Roots of all Powers,

RULE,

1. Prepare the given number for extraction, by pointing off from the unit's place, as the required root directs.

2. Find the first figure of the root by trial, and subtract its power from the left hand period of the given number.

3. To the remainder bring down the first figure in the next period, and call it the dividend.

4. Involve the root to the next inferior power to that which is given, and multiply it by the number denoting the given power, for a divisor.

5. Find how many times the divisor may be had in the dividend, and the quotient will be another figure of the root.

6. Involve the whole root to the given power, and subtract it (always) from as many periods of the given number as you have found figures in the root.

7. Bring down the first figure of the next period to the remainder for a new dividend, to which find a new divisor as before, and in like marner proceed till the whole be finished.

NOTE.—When the number to be subtracted is greater than those periods from which it is to be taken, the last cuotient figure must be taken less, &c.

[ocr errors][ocr errors][ocr errors]

EXAMPLES.

[ocr errors]

1. Required the cube root of 135796,744 by the above general method.

135796744(51,4 the root.
125=1st subtrahend.

5)107 dividend.

132651=2d subtrahend. 7803) 31457=2d dividend.

135796744=3d subtrahend.

5 X5 X3=75 first divisor.
51 x 51 x 51=132651 second subtrahend.
51 x 51 x 3=7803 second divisor.

514 X 514 X 514=135796744 3d subtrahend. 2. Required the sursolid or 5th root of 6436343.

6436343(23 root.
32

[ocr errors][merged small]

2x2x2x2x5=80)323 dividend.

23 x 23 x 23 x 23 x 23=6436343 subtrahend. NOTE.--The roots of most powers may be found by the square and cube roots only; therefore, when any ereu power is given, the easiest method will be (especially in a very high power) to extract the square root of it, which reduces it to half the given power, then the square root of that power

reduces it to half the same power; and so on, till you come to a square or a cube.

For example: suppose a 12th power be given; the squaro root of that reduces it to a 6th power: and the square roof of a 6th power to a cube.

Wha

per b.;

EXAMPLES.

3. What is the biquadrate, or 4th root of 199871733761

Ans. 376. 4. Extract the square, cubed, or 6th root of 12230590 464.

Ans. 48. 5. Extract the square, biquadrate, or Sth root of 72139 95789338836.

Ans. 96.

4 C.: mai

5 ed. at

ALLIGATION, IS the method of mixing several simples of different qualities, so that the composition may be of a mean or middle quality: It consists of two kinds, viz. Alligation Medial, and Alligation Alternate.

ALLIGATION MEDIAL, Is when the quantities and prices of several things are given, to find the mean price of the mixture composed of those materials.

RULE. As the whole composition : is to the whole value : : so berekend is any part of the composition : to its mean price.

EXAMPLES.
1. A farmer mixed 15 bushels of rye, at 64 cents a bush-
el, 18 bushels of Indian corn, at 55 cts. a bushel, and 21
bushels of oats, at 28 cts. a bushel; I demand what a
bushel of this mixture is worth?

bu. cts. $cts. bu. $ cts. bu.
15 at 6459,60 As 54 : 25,38 : :1
18 55–9,90

1
21 285,88

-cts.

54)25,38(,47 Ans. 54 25,38 2. If 20 bushels of wheat at 1 dol. 35 cts. per bushel be mixed with 10 bushels of rye at 90 cents per bushel, what will a bushel of this mixture be worth ?

Ans. $1,20 cts. 3. A tobacconist mixed 36 lb. of tobacco, at Is. 6d. per lb. 12 lb. at 2s. a pound, with 12 lb. at 1s. 10d. per 1b.; what is the price of a pound of this mixture ?

Ans. ls. 8d. 4. A grocer mixed 2 C. of sugar at 56s. per C, and 1 C. at 43s. per C. and 2 Č. at 50s. per C. together; I demand-the price of 3 cwt. of this mixture ? Ans. £7 13s.

5. A wine merchant mixes 15 gallons of wine at 4s. ed.

per gallon, with 24 gallons at 6s. 8d. and 20 gallons at 6s. 3d. ; what is a gallon of this composition worth?

Ans. 5s. 10d. 21 grs.

[ocr errors]
[ocr errors]
[ocr errors]

6. A grocer hath several sorts of sugar, viz. one sort at 8 dols. per cwt. another sort at 9 dols. per cwt. a third sort # at 10 dols. per cwt. and a fourth sort at 12 dols. per cwt. and he would mix an equal quantity of each together; 1 demand the price of 3) cwt. of this mixture ?

Ans. $34 12 cts. 5 m.

1 7. A goldsmith melted together 5 lb. of silver bullion, A of 8 oz. fine, 10 lb. of 7 oz. fine, and 15 lb. of 6 oz. fine; wort pray what is the quality or fineness of this composition? per

Ans. 6 oz. 13 pwt. 8 gr. fine. 8. Suppose 5 lb. of gold of 22 carats fine, 2 lb. of 21 carats fine, and 1 lb. of alloy be melted together ; what is the quality or fineness of this mass?

20 Ans. 19 carats fine.

[ocr errors]
[ocr errors]

riz.

lity ALLIGATION ALTERNATE,

12 IS the method of finding what quantity of each of the As ingredients whose rates are given, will compose a mixture 3. of a given rate; so that it is the reverse of Alligation Me

per dial, and may be proved by it. CASE I.

4. When the mean rate of the whole mixture, and the rates of all the ingredients are given, without any limited quan. tity.

laay

A RULE. 1. Place the several rates, or prices of the simples, be 48. a ing reduced to one denomination, in a column under each ther, other, and the mean price in the like name, at the left hand

muc 2. Connect, or link the price of each simple or ingredi- An ent, which is less than that of the mean rate, with one of any number of those, which are greater than the mean rate, and each greater rate, or price, with one, or any num. 6. ber of the less.

cts. 3. Place the difference, between the mean price (or mix, at 8 ture rate) and that of each of the simples, opposite to the mix rates with which they are connected.

5.

[ocr errors]

4. Then, if only one difference stands against any rate, It will be the quantity belonging to that rate, but if there be several, their sum will be the quantity,

EXAMPLES.

[ocr errors]

3

Answer

[ocr errors]

1. A merchant has spices, some at 9d. per lb. some at Is. some at 2s. and some at 2s. 6d. per lb. how much of each sort must he mix, that he may sell the mixture at ls. 8d. per pound? d. 16. d.

d. 16. 9 10 at 97

4 d. 12 4 12 1 Gives the d. | 12 10 20) 24 8 24 | Answer; or

20 24 ) 11 30 11 30

30 2. A grocer would mix the following qualities of sugar; riz. at 10 cents, 13 cents, and 16 cents per lb. ; what quantity of each sort must be taken to make a mixture worth 12 cents per pound ? Ans. 5 lb. at 10 cts. 2 lb. at 13 cts. and 2 lb. at 16 cts. per lh.

3. A grocer has two sorts of tea, viz. at 9s. and at 15s. per lb. how must he mix them so as to afford the composiion for 12s. per lb. ?

Ans. He must mix an equal quantity of each sort.
4. A goldsmith would mix gold of 17 carats fine, with
Rome of 19, 21, and 24 carats fine, so that the compound
Taay be 22 carats fine ; what quantity of each must he take?

Ans. 2 of each of the first three sorts, and 9 of the last.

5. It is required to mix several sorts of rum, viz. at 58. Side 7s. and 9s. per gallon, with water at per gallon, togeed ther, so that the mixture may be worth 6s. per gallon; how

much of each sort must the mixture consist of ?
Ans. I gal. of rum at 5s., 1 do. at 7s., 6 do, at 9s. and 3 gals.
water. Or, 3 gals, rum at 5s., 6 do. at 7s., 1 do. at 9s. and

1 gal. water.
6. A grocer hath several sorts of sugar, viz. one sort at 12
cts. per lb. another at 11 cts. a third at 9 cts. and a fourth
at 8 cts. per lb. ; I demand how much of each sort he must
mix together, that the whole quantity may be afforded at
10 cents per pound ?

hari

[ocr errors]

DE - DE

[ocr errors]
« ΠροηγούμενηΣυνέχεια »