The Western Practical Arithmetic; Wherein the Rules Are Illustrated, and Their Principles Explained Containing a Great Variety of Exercises, Particula (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1838 edition. Excerpt: ...days, -at 6 per cent. per annum? Ans. $8 80. 4. What is the interest of 3459 dollars, for 75 days, at 6 per cent. per annum? Ans. $43 23 cts. 7 m.-5. What is the interest of 1500 dollars, for 60 days, at 5 per cent. per annum? Ans. $12 50. Case 5. Hie amount, time, and rate per cent. given, to find the principal. Rule.--Find the amount of 100 dollars for the time required, at the given rate per cent. Then, by proportion, as the amount of 100 dollars for the time required, (at the given rate per cent.) is to the amount given, so is 100 dollars to the principal required. EXAMPLES. 1. What principal, at interest for 8 years, at 5 per ct. per annum, will amount to 840 dollars? Ans. $600. 5 dollars 8 years 40 Int. of $100 for 8 yr. 100 $ ' $ $ $, 140: 840:: 100:600 140 Amt. of $100 for 8 yr. 2. What principal, at interest, for 6 years, at 4 per cent. per annum, will amount to $1240. Ans. $1000 3. What principal, at interest for 5 years, at 6 per ct. per annum, will amount to 2470 dollars? Ans. $1900. Case 6. The principal, amount, and time given, to find the rate per cent. Rule.--Find the interest for the whole time given, by subtracting the principal from the amount. Then, as the principal is to 100 dollars, so is the interest of the principal for the given time, to the interest of 100 dollars for the same time. Divide the interest last found by the time, and the quotient will be the rate per cent. per annum, Or by compound proportion. EXAMPLES. 1. At what rate per cent. per annum, will 600 dollars amount to 744 dollars, in 4 years? Ans. 6 per cent. $744 amount As 600: 100:: 144: 24. 600 principal yr. $ 4) 24 (6 rate per cent. 144 interest ' Or by compound proportion: As 600: 100 $ $ yr. yr.:: 144: 6 rate per cent. 4:1 2. At what rate per cent. pe