MODEL OPERATION. 1. $0.08×3=$0.266; $0.266+$1-$1.266. ANALYSIS.-1. If the interest of $1 for one year is $0.08, for 3 years it will be 3 times $0.08, which is $0.266; and the amount is the sum of $0.266 and $1, which is $1.266. 2. If $1.266, the amount of $1 for the given time and rate, require $1 principal, $73.86 will require as many dollars principal as $1.266 is contained times in $73.86, which are 58.341. Therefore, the amount $73.86 for 3 yrs. 4 mo., at 8 per cent., require $58.341 principal. NOTE.-Require the pupil to write a rule from the formula. 627. What principal, in 8 years, at 8 per cent., will amount to $800.80? 628. What principal, in 4 years 6 months, at 6 per cent. interest, will amount to $80.50 ? 629. What principal, in 2 years 4 months 16 days, at 51⁄2 per cent. interest, will amount to $89.25? 630. What principal, in 5 years 9 months 7 days, at 7 per cent. interest, will amount to $148.69? QUESTIONS.-What is a tax? (217.) How are taxes assessed? What is a poll tax? (219.) What is real estate? (220.) What is personal property? (221.) What is an inventory? (222.) What is the method of assessing taxes? (223.) For what purpose are tax tables constructed? What are duties? (224.) What is a custom house? (225.) What is a port of entry? (226.) LESSON LXXVII. 255. Prob. IV.-Given the principal, time and interest, to find the rate per cent.? I receive $25 interest for the use of $325 for 2 years 9 months; what is the rate per cent.? MODEL OPERATION. 1. $325.01X23=$8.937. 2. $258.937-2.79+ per cent. ANALYSIS.-1. If the interest of $325, at 1 per cent., for 1 year, is $3.25, for 23 years it will be 23 times $3.25, which is $8.937. 2. If $8.937, the interest on $325 for the given time, requires the rate of 1 per cent., $25, the interest on $325 for the same time will require as many times the 1 per cent. as $8.937 is contained times in $25, which is 2.79+. Therefore, if I receive $25 interest for $325, for 2 years 9 months, the rate per cent. is 2.79+. NOTE.-Require the pupil to write a rule from the formula. 631. A man pays $14 for the use of $40 for 5 what is the rate per cent.? years; 632. A man paid $10 for the use of $100 for 1 year 8 months; what is the rate per cent.? 633. At what per cent. must $875 be loaned, to gain $125 in 2 years? 634. At what rate per cent. will $4820, in 5 months, gain $18.50 interest? 635. At what per cent. will $25.48, in 3 years 3 months 12 days, give $2 interest? 636. If $246.44 are paid for the use of $840 for 5 years and 5 months, what is the rate per cent.? 637. If $28.41 are paid for the use of $120 for 2 years 1 month and 27 days, what is the rate per cent.? 638. A gentleman deposited $625 in a savings bank, from which he receives $8.52 every 3 months; what per cent. interest does he receive? 639. If I borrow $1020 for 1 year 6 months and 15 days, and pay $85.75 interest, what is the rate per cent.? 640. A man built a vessel at the expense of $450000, and it brought him in $38,000 per year; what per cent. interest did his money yield him? 641. If a capitalist invests $18048 in railroad stock, and draws a quarterly dividend of $525.94, at what rate per cent. does he receive interest? QUESTIONS.-What is tonnage? (227.) What is revenue? (228.} What are ad valorem duties? (229.) What are specific duties? (230.) What is an invoice? (231.) What is tare? (232.) What is leakage? (233.) What is breakage? (234.) What is gross weight? (235.) What is net weight? (236.) Give the analysis of finding the amount of duty on an invoice of goods. (237.) What is interest? (238.) What is the principal? (239.) LESSON LXXVIII. 256. Prob. V.-Given the principal, interest and rate per cent., to find the time. In how long a time will $343, at 7 per cent. interest, gain $90? MODEL OPERATION. 1. $343X.07=$24.01. 2. $90÷24.01 3.748 yrs.+, 3 yrs. 8 mo. 29 da. ANALYSIS.-1. If the interest of $1 for 1 year is $0.07, for $343 it is 343 times $0.07, which is $24.01. 2. If, to gain $24.01, at 7 per cent., $343 requires 1 year to gain $90, it will require as many years as $24.01 are contained times in $90, which is 3.748+, equal to 3 years 8 months 29 days. Therefore, it will require 3 years 8 months 29 days for $343 to gain $90, at 7 per cent. NOTE.-Require the pupil to write a rule from the formula. 642. How long will it take $450, at 6 per cent., to gain $12.48 interest? 643 How long will it take $5040, at 7 per cent., to gain $180.44 interest? 644. How long will it take $9000, at 5 per cent., to gain $430.88 interest? 645. A man loaned $848.89 at 3 per cent., and received $98.56 interest; how long was it loaned? 646. In what time will a given principal double itself at 6 per cent. interest? at 7 per cent.? at 8 per cent.? at 9 per cent.? at 5 per cent.? at 4 per cent.? at 5 per cent.? at 10 per cent.? 647. In what time will $8648.50 amount to $9988, at 7 per cent.? at 6 per cent.? 648. In what time, at 7 per cent., will $1000 gain $100 interest? 649. A man loaned $8999.86 at 8 per cent., and received $168.50 interest; how long was it loaned? 650. In what time will $21000, at 6 per cent., gain $8460.43 interest? · QUESTIONS.-What is rate per cent.? (240.) What is the amount? (241.) What is simple interest? (242.) What is compound interest? (243.) What is legal interest? (244.) Give the analysis of finding the interest on a given principal for a given time. (245.) Write a rule from the analysis. Give the analysis of finding the interest on a given principal by the 6 per cent. method. (246.) Write a rule from the analysis. Repeat the table. (247.) What are partial payments? (248.) What is an indorsement? (249.) Give the Supreme Court rule for casting interest, when partial payments have been made. (250.) LESSON LXXIX. 257. COMPOUND INTEREST. 258. Interest is added to the principal annually, semi-annually, or quarterly, as the parties agree.* What is the compound interest on $250 for 2 years 3 months and 12 days, at 6 per cent.? MODEL OPERATION. 1. $250X.06 $15; $250+$15-$265, am't 1st year. 2. $265X.06=$15.90; $15.90+$265-$280.90, am❜t 2nd year. 3. $280.90.017-$4.775; $4.775+$280.90=$285.675, am't for 3 mo 12 da. 4. $285.675-$250-$35.675, compound interest for 2 years 3 months 12 days. ANALYSIS.-1. If the interest on $1 for one year is $0.06, on $250 it is 250 times $0.06, which is $15; $15 added to the principal equals $265, the amount. 2. If the interest on $1 for one year is $0.06, on $265 it is 265 times $0.06, which is $15.90; this added to the principal equals $280.90, the amount. 3. If the interest on $1 for 3 months and 12 days is $0.017, for $280.90 it is 280.90 times $0.017, which is $4.775, which added to the principal gives $285.675. 4. If the amount for 2 yrs. 3 mo. 12 da. is $285.675, and the principal is $250, the interest is the difference of these numbers, which is $35.675. Therefore, the compound interest on $250 for 2 yrs. 3 mo. 12 da., at 6 per cent., is $35.675. FORMULA: A.-P.-I. *NOTE. It is not legal to receive compound interest, but if annual, semi-annual, or quarterly interest is mentioned in the note, it can be collected when due. |