To find the interest of any sum, when the rate is not 6 per cent., we have the following

RULE.

I. How do you proceed? A. Find the interest for 6 per cent. as before.

II. How do you proceed next? A. Multiply the interest of 6 per cent. by the given rate, and always divide by 6.

1. What is the interest of $600 for 1 yr. 2 mo. and 15 days, at 5 per cent.?

600

2. What is the interest of $240 for 2 yrs. 6 mo. at 1 per cent. ? (6) At 2 per cent.? (12) At 4 per cent.? (24) At 6 per cent.? (36) At 10 per cent.? (60) At 53 per cent.? (33) A. $171.

3. What is the interest of $480 for 3 yrs. 2 mo., at 15 per cent.? (228) At 20 per cent.? (304) At 10 per cent.? (16340) At 15 per cent. ? (23560) At 7 per cent.? (10640) Á. $1037,40.

4. What is the interest of $600 for 15 mo., at 23 per cent.? (20625) At 33 per cent.? (28125) A. $48,75.

5. What is the interest of $600 from January 1st to March 1st? (6) From January 15th to May 15th? (12) From Janua ry 15th to September 15th? (24) A. $42.

6. What is the amount of $500 from March 10th, 1824, to March 10th, 1827? (590) From March 29th, 1820, to March 29th, 1826? (680) From March 16th, 1820, to March 16th, 1824? (620) A. $1890.

7. What is the interest of $60 from June 1st, 1826, to November 1st, 1827? (510) From April 1st, 1825, to August 16th, 1826? (495) From July 4th, 1825, to August 19th, 1828? (1125) A. $21,30

8. What is the interest of $300 from September 5th, 1826, to September 25th, 1826? (1) From August 9th, 1826, to December 24th, 1827? (2475) A. $25,75.

9. What is the amount of $180 from October 1st, 1826, to December 1st, 1830?, A. $225.

¶ LXIV. A concise and practical Rule for the State of New York, in which the interest is established by law at 7 per cent. It has been remarked, that 7 per cent. is of 6 per cent.; that is, more than 6 per cent: Hence,

Q. To find the interest at 7 per cent., what is the

RULE?

A. Add of the interest, at 6 per cent. (found as before), to itself; the sum will be the interest at 7 per cent.

Note. The interest for any rate per cent. may be found in the same manner by subtracting, when the given rate is under 6 per cent., and adding, when

it is more.

1. What is the interest of $360 for 20 days, at 7 per cent.?

2. What is the interest of $60 for 2 yrs. 4 mo., at 7 per cent.? A. $9,80.

7

3. What is the amount of $120,60 for 1 yr., 6 mo., 10 da., at per cent. ?

A. $133,497

m.

4. What is the amount of $241,20 for 6 mo. 20 da.? (25058) For 1 mo. 1 da.? (242653) For 1 yr. 4 mo. 5 da.? (263946) For yrs. 6 mo. 25 da.? (284582) A. $1041,761+.

2

¶ LXV. Since 6 per cent. is $6 on $100, that is, To of the principal, and per cent. To, &c., hence,

To calculate the interest at any rate per cent., when the time is 1 year, we proceed as follows:

RULE. Multiply by the given rate, and cut off two figures, as before.

1. What is the interest of $220,40 for 1 yr., at 9 per cent?

$220,40

9

$19,8360 Ans.

2. What is the interest of $1200,30 for 1 yr., at 12 per cent.? A. $150,03,7.

3. What is the amount of $80,10, for 1 yr., at 2 per cent,? (82102) At 5 per cent.? (84105) At 10 per cent.? (8811) At 4 per cent.? (83704) At 194 per cent.? (95919)

A. $433,94+.

¶ LXVI. COMMISSION. Q. When an allowance of so much per cent. is made to a person called either a correspondent, factor, or broker, for buying, or assisting in buying and selling goods for his employer, what is it called? A. Commission.

RULE. Since commission, insurance, buying and selling stocks, and loss and gain, are rated at so much per cent., without regard to time, how may all these be calculated? A. Multiply by the rate per cent., and cut off two figures, as in the last rule.

1. What would you demand for selling $400 worth of cotton, for 2 per cent. commission?

$400 X 21, and cutting off two figures, $10, commission, Ans.

2. My correspondent informs me that he has purchased goods to the amount of $5000; what will his commission amount to, at 2 per cent.? A. $125.

3. What must I be allowed for selling 300 pounds of indigo, at $2,50 per lb., for 2 per cent. commission? (15) For 2 per cent.? (20625) For 5 per cent.? (3750) For 6 per cent.? (4875) For 7 per cent.? (5250). A. $174,37).

INSURANCE. Q. What is the allowance of so much per cent. made to persons, to make good the losses sustained by fire, storms, &c. called? A. Insurance.

Q. By what name is the instrument that binds the contracting parties called? A. Policy.

Q. What is the sum paid for insurance called? A. Premium. 1. What will be the premium for insuring an East India ship, valued at $25000, at 15 per cent.? A. $3875.

2. What is the premium for insuring $2600, at 20 per cent.? (520) At 30 per cent.? (780) At 18 per cent.? (481), 26 per cent.? (689) A. $2470.

STOCK. Q. What is the general name for all moneys invested in trading companies, or the funds of government, called? A. Stock.

Q. When $100 of stock sells for $100, how is the stock said to be A. At par.

Q. When is it said to be above par, and when below par? A. When $100 stock sells for more than $100, it is said to be above par; when for less than 100, below par.

Q. When it is above par, what is it said to be? A. So much advance.

1. What is the value of $2500 of stock, at 106 per cent.; that is, 6 per cent, advance? Ans. $2500 × 106 $2650. 2. What is the value of $1000 of insurance stock, at 95 per cent.; that is, 5 per cent. below par? A. $950.

3. What is the value of $1200 of bank stock, at 3 per cent. below par; that is, 97 per cent.? (1164) At 112 per cent., or 12 per cent. advance? (1344) At 87 per cent.? (1050) At 124 per cent. advance; that is, 112 per cent.? (1350) Á. $4908.

LOSS AND GAIN. 1. Bought a piece of broadcloth for $80; how much must. I sell it for, to gain 10 per cent.; that is, 10 per cent. advance, which is 110 per cent. on the cost? $80 × 110 $88, Ans.

2. Bought a hogshead of molasses for $50, and 5 gallons having leaked out, I sold the remainder at 10 per cent. loss; that is, 10 per cent. below par, being 90 per cent. on the cost; what did I get for it? A. $45.

3. If I pay $50 for a piece of broadcloth, how must I sell the same so as to gain 20 per cent.; that is, 20 per cent. advance, or 120 per cent on the cost? A. $60.

4. Bought rum at $1,25 per gallon; and, by accident, so much leaked out, that I am content to lose 20 per cent.; how must I sell it per gallon? A. $1.

5. A merchant bought 400 barrels of flour for $3500; how must he sell it per barrel, to gain 25 per cent.? A. $10,934.

6. Bought sugar at 15 cents per lb.; at what rate must I sell it a lb. so as to gain 20 per cent.? (18) So as to gain 25 per cent.? (1875) 30 per cent.? (195) 40 per cent.? (21) 45 per cent.? (2175) 50 per cent.? (225) 65 per cent.? (2475) 75 per cent.? (2625) 90 per cent.? (285) 100 per cent., or to double my money? (30) A. $2,31.

7. Bought 100 tierces of rice, each tierce weighing 300 lbs.. net, at 64 cents per lb.; (1875) 30 pipes of wine for $1,124 per gallon; (425250) 3 hhds. of rumi for 90 cents per gallon; 17010) 40 barrels of flour for $7 per barrel; (300) and 40 bushels of salt for 7 s. 6 d. or $1,25 per bushel; (50) how much must all the said articles be sold for, to gain 50 per cent., being 150 per cent. on the first cost? A. $9971,40.

¶ LXVII. Time, Rate per cent., and Amourt given, to find the Principal.

1. What sum of ready money, put at interest fbz1 yr. 8 mo. at 6 per cent., will amount to $220?.

The amount of $1 for 1 year and 8 mo. is $1,10; then $220 ÷ $1,10 = $200, "Ans.

RULE. How, then, would you proceed to find the principal ? A. Divide the given amount by the amount of $1, at the given rate and time.

2. What principal, at 6 per cent., in 5 years, will amount to $650?

In this example, in dividing $650 by $1,30, we annex two ciphers to 500, to make the decimal places in the divisor and dividend equal. (ScoT LVI.) A. $500. 3. What principal, at 6 per cent., in 1 year 2 mo., will amount to $642. A. $600.

4. What principal will amount to $691,50 in 2 yrs., 6 mo., 15 da., at 6 per cent.? A. $600.

5. A correspondent has in his hands $210, to be laid out in goods; after deducting his own commission of 5 per cent., how much will remain to be laid out.

It is evident, that the commission which he received, added to the money laid out, must make $210; hence, $210 may be considered the amount, and the money laid out the principal; consequently, the question does not differ mate rially from the foregoing. In such questions as these, in which time is not regarded, the amount of $1 is the rate per cent. added to $1.

It will be recollected that 6 per cent. is 6 cents on 100 cents, or $1; 5 per cent., 5 cents; the amount, then, of $1, at 5 per cent., is 5 cents added to $1, making $1,05; then $210 $1,05= = $200, Ans.

6. A factor receives $1040 to be laid out in goods, after deducting his own commission of 4 per cent. ; how much does his commission amount to?

The sum laid out, found as before, is $1000; then, 1040-1000 = $40, commission, the Answer.

7. A factor receives $2100, from which he wishes to deduct his commission of 5 per cent.; what will his commission amount to? A. $100.

DISCOUNT. 1. William owes Rufus $1272 to be paid in 1 year, without interest; but Rufus, wanting his money immediately, says to William, I am willing to allow you 6 per cent., the lawful interest, if you will pay me now; what sum ought William to pay Rufus?

It is evident that he ought to pay just such a sum, as, put at interest, would in 1 year amount to $1272; or, in other words, such a principal as would amount to $1272. This question, therefore, is solved in the same manner as the preceding.

$1272

$1,06=1200, the Ans.