Εικόνες σελίδας
PDF
Ηλεκτρ. έκδοση

SIMPLE INTEREST. 462. Interest is money charged for the use of money.

463. The Principal is the sum for which interest is charged. Interest is reckoned as a percentage of the principal

464. The Rate of interest is the rate per cent on $1 'or a certain time. The usual time is one year.

465. The Time is the period during which the money is on interest.

466. The Amount is the sum of the principal and interest.

467, Simple Interest is interest on the principal only. Compound Interest is interest also on the interest.

468. Legal Interest is interest at the rate fixed by law. It varied in different States in 1894 as follows:

[merged small][merged small][merged small][merged small][merged small][ocr errors][merged small]

6

6

.

7/ *

6

6

6

6

6

Alabama. 8! 8 Kentucky.

6 North Dakota. 7) 12 Alaska. 8 10 Louisiana. 5 8|Ohio..

8 Arizona . 7 * Maine 6 * Oklahoma

712 Arkansas 610 Maryland.

6
6 Oregon.

8 10 California

Massachusetts. * Pennsylvania 6 Colorado.

8 Michigan . 6 8 Rhode Island 61 * Connecticnt 6 6, Minnesota. 7 10 South Carolina. 7 8 Delaware

6 6 Mississippi 6 10 South Dakota. 7112 Dist.Columbia. 6 10 Missouri

6 8 Tennessee.

6 Florida 8) 10 Montana 10 * Texas

6 10 Georgia 7 8 Nebraska . 7 10 Utah.

8) * Idaho. 10 18|Nevada .

7 * | Vermont.

6 6 Illinois.

5 7New Hampshire. 6 6 Virginia. Indiana 6 8 New Jersey . 6 6 Washington.

8) * Indian Ter

6 10 New Mexico. 6 12 West Virginia. 6 Jowa 6 8 New York. 6 6 Wisconsin

6 10 Kansas

6 10 North Carolina. 61 8|Wyoming. The first column gives the legal rate; second column, the rate that may be agreed upon; the * indicates no limit to the rate.

469. Usury is a rate of interest greater than the law allows. Various penalties are attached to taking usury.

The legal rate in England and France is 5%; and in Ireland, Canada, and Nova Scotia is 6%.

In notes, contracts, accounts, mortgages, etc., when no rate 18 speci. fied, the legal rate is understood.

[ocr errors]
[ocr errors]

6

[ocr errors]

12 *

Notes draw interest after they become due, though interest is not men. tioned in them; and interest is reckoned on book accounts after the er. piration of the term of credit.

470. The Quantities are five: 1. The Principal; 2. The Interest ; 3. The Rale; 4. The Time ; 5. The Amount.

Note.-In computing interest it is customary to reckon a month as he uf a year, and a day as sy of a month. In dealing with the U. S. Govordment, each day is sts of a year.

CASE I.

471. Given, the principal, the rate per cent., and the time, to find the interest or the amount.

MENTAL EXERCISES.

1. What is the interest of $80 for yr. 6 mo. at 6%?

SC:UTION.-6 months equal fe or 4 of a year, which with 2 yr. equals 24, or { years. At 6 per cent. for 1 yr., 187 of the principal equals the Interest, and för 24 or yr., 3 times Ifo or 18 or at of the principal equals the interest, zo of $80 equals $12.

What is the interest of 2. $60 for 6 yr, at 5%?

6. $300 for 4 yr. 6 mo. at 6%? 3. $40 for 4 yr. at 5%?

7. $240 for 3 yr. 9 mo. at 8%? 4. $30 for 5 yr. at 4%?

8. $330 for 7 yr. 6 mo. at 4%? 5. $600 for 2 yr. 3 mo. at 8%? 9. $500 for 3 yr. 7 mo. 6 da, at 5%? 10. What is the interest of $300 for 5 yr. 3 mo. 18 da. at 10%? 11. What is the interest of $500 for 2 yr. 2 mo. 12 da. at 5%? 12. What is the amount of $50 for 2 yr. 8 mo, at 6 per cent.?

REMARK.-We find that ug or of the principal equals the interest, hence 3 of the principal equals the amount; 1} of $50=$58.

13. What is the amount of $600 for 7 yr. 6 mo. at 6 per cent.? 14. What is the amount of $300 for 8 yr. 10 mo. at 6 per cent?

METHOD FOR YEARS.

1. What is the interest of $2400 for 6 yr. 7 mo. 15 du., at

7%)

OPERATION.

SOLUTION.-By reduction, we find that 6 yr. 7 mo. 15 da. equals 61 yr. At 7%, .07 times $2400 equals

$2400 the interest for 1 year, which is $168; if the inter

.07 est for 1 year is $168, for 6; yr. it is 63 times $168, which by multiplying we find is $1113. Hence the

$168.00 following

63

$1113.00 Ana Rule.-I. Multiply the principal by the rate, and that product by the time expressed in years, to find the interest

II. Add the interest to the principal to find the amount.

WRITTEN EXERCISES. Required the interest 2. Of $360 for 3 yr. 6 mo. at 7%? 3. Of $940 for 7 yr. 8 mo. at 6 %? 4. Of $860 for 5 yr. 9 mo. at 5%? 5. Of $780 for 8 yr. 4 mo. at 7 %.? 6. Of $590 for 3 yr. 10 mo. at 8%? 7. Of $1296 for 5 yr. 10 mo. 15 da. at 6%? 8. Of $4080 for 3 yr. 3 mo. 9 da. at. 5%?

Ans. $88.20. Ans. $432.40. Ans. $247.25.

Ans. $455. Ans. $180.93. Ans. $456.84. Ans. $668.10.

SIX PER CENT. METHOD. 472. The Six Per Cent. Method is 80-called because the

process is based upon that rate. 1. What is the interest of $240 for 6 yr. 8 mo. 18 da. at 6 %?

Solution. The Int. of $1 for 1 yr. is $0.06, OPERATION, and for 6 yr. it is 6 times $0.06, or $0.36. The Int. of $1 for 1 mo., or is of a year, is

6X.06=$0.36 its of 69, or of a cent, and the Int. for 8 mo.

3x 8- .04 is 8 tiiness of a cent, or $0.04.

X 18.003 The Int. of $1 for 1 mo., or 30 da., is of a

$0.403 cent, or 5 mills, and for 1 day it is so of 5

240 mills, or & of a mill, and for 18 days it is 18

$96.72 times of a mill, or $0.003.

Adding these results, we have $0.403 as the Int. of $1 for 6 yr. 8 mo, and 18 da., and on $240 it is 240 times $0.403, or $96.72.

Rule.-I. Multiply the rate, .06, by the number of years; take 1 of the number of months as cents, und of the nuinber of days as mills ; their sum will be the interest of $1 for the given time at 6%.

II. Multiply this sum by the principal, and the product will be the interest of the principal at 6%. For any other rate, take as many sixths of this interest as the rate is of six.

NOTES.-1. Another method is to reduce the years to months, and take half the nuinber of months for cents, etc., as before.

2. Another method is to take the number of months as cents, and one-third of the uumber of (lays ils mills, and multiply the sum by half the principal.

3. The inethod for days popularly expressed is, “Multiply dollars by days und divide by 6000."

WRITTEN EXERCISES. Roquired the interest 2. Of $350 for 3 yr. 4 mo. 12 da. at 6%.

Ans. $76.76. 3. Of $975 for 5 yr. 6 mo. 6 da. at 6%. Ans. $322.721. 4. Of $834 for 9 yr. 10 mo. 15 da. at 6%. Ans. $494.144. 5. Of $15.95 for 8 yr. 6 mo. 24 da. at 7%. Ans. $27.55+

6. Of $23.75 for 7 yr. 7 mo. 21 da. at 5%. 7. Of $.325 for 9 yr. 5 mo. 14 da. at 8%. 8. $147.37}, 4 yr. 11 mo. 13 da., 7%. 9. $635.625, 9 yr. 9 mo. 11 da., 9%. 10. $387.184, 10 yr. 7 mo. 7da., 10%. 11. $570.05, 3 yr. 5 mo. 5 da., 6} %. 12 $980.81%, 5 yr. 9 mo. 17 da., 74%.

Ans. $9.07+.
Ans. $.24+.

Ans. $51.094.
Ans. $559.51 +.
Ans. $410.53+.
Ans. $127.11+.
Ans. $440.66t..

.36- "6

THE 60 DAY METHOD. 473. At 6% a year, the rate for 2 mo., or 60 da., is 1% hence for 60 da., ido of the principal equals the interest. From this we have the following method called the 60 Day Method.

Rule.Point of two places in the principal for the interest for 60 days, and take multiples or aliquot parts of this interest for any other number of days.

1. What is the interest of $360 at 6% for 66 da.? for 96 da.? SOLUTION.- Pointing off two places

OPERATION. we have $3.60, the Int. for 60 da.; then $3.60 Int. for 60 da. take it of $3.60, we have $0.36, the Int.

6 da. for 6 da.; then the sum of these inter

$3.96ests, or $3.96, is the interest for 66 da.

SOLUTION.-Pointing off two places we have $3.60, the Int. for 60 da.; take

$3.60 Int. for 60 da. of $3.60 for the Int. for 30 da.; and to 1.80of $3.60 for the Int. for 6 da.; their sum

.36%

6 da. is the Int. for 96 da.

$5.76–

" 96 da. 2. Find the Int. of $720, at 6%, for 6 mo. 12 da. For 128 da OPERATION.

OPERATION. $7120_Int. for 60 da.

$720--Int. for 60 da. 2160_ 6 mo. (3X2 mo.)

14 40"

“ 120 da. 10 da. (f of 60 da.)

172

6 da. 2 da. (1 of 10 da.)

124

“ 66 da.

OPERATION.

[ocr errors]

" 30 da.

66

1 2016
1242 16

2 da. $23.04- Int. for 6 mo. 12 da.

$15.36 16

" 128 da.

WRITTEN EXERCISES. Required the interest 3. Of $1500 for 4 mo. at 6%. 4. Of $780 for 10 mo. at 6%. 5. Of $960 for 2 mo. 9 da. at 6%. 6. Of $1260 for 33 da. at 6%. 7. Of $800 for 63 da. at 6%. 8. Of $150 for 135 da. at 6%.

Ans. $30.

Ans. $39. Ans. $11.04. Ans. $6.93. Ans. $8.40. Ans. 83.37}

9. Of $840 for 3 mo. 28 da. at 6%.

Ans. $16.52. 10. Of $1250 for 4 mo. 29 da. at 7%.

dns. $36.2111. Of $250 for 1 yr. 9 mo. 12 da. at 7%. Ans. $31.2112. Of $875 for 2 yr, 3 mo. 24 da. at 8%. Ans. $162.17, 13. Of $275.50 for 2 yr. 8 mo. 15 da. at 5%. Ans. $37.31— 14. Of $360.50 for 5 yr. 4 mo. 16 da. at 41%. Ans. $87.24+.

15. On a 3 mo, note for $3600, dated April 15, 1876, at 6%, exact time. EXACT TIME.

OPERATION.
In April,
15 da.

$3600= Int. for 60 da.
In May,
31 da.

18/00

" 30 da. In June, 30 da.

60

1 da. In July, 15 da.

$54.60 91 da. 16. On a 3 mo, note for $2400, dated Feb. 20, 1887, at 6%, exact time?

Ans. $35.60. 17. Of $750, for May 12 to Oct. 20, at 6%, exact number of days?

Ans. $20.125. 18. Of $180, from June 16 to Nov. 10, at 7%, exact number of days?

Ans. $13.72. 19. On a note for $570, dated Nov. 24, 1887, and due Feb. 10, 1888, at 6%, allowing 3 da. of grace ?

Ans. $7.595. 20. On a note for $1050, dated Oct. 16, 1887, and due Mar. 25, 1888, at 6%, allowing 3 da. of grace ?

Ans. $28.70.

METHOD BY CANCELLATION. 474. The following Six Per Cent. Method by Cancellation will be found convenient and practical :

Rule for Months.-Point off two places in the principal, divide by 2, and multiply by the number of months.

For the Int. for 2 mo. is Ido of the principal, and for 1 mo. it is of ato of the principal; hence the above rule.

Rule for Days.—Point of three places in the principal, dj. vide by 6, and multiply by the number of days.

For the int. for 2 mo. or 60 days is too of the principal, and for 8 da. it is ty of ido, or tooo of the principal, and for 1 da. it is of Totoo of the principal; hence the above rule.

1. What is the Int. of $2400 for 38 mo. at 6 %? at 7%?

SOLUTION.- We point off two places in OPERATION. $2400 to divide by 100, then divide by 2, and

$24.00X38 multiply by 38; cancelling and multiplying,

-$456. we have $456.

[ocr errors]
« ΠροηγούμενηΣυνέχεια »