51. The six per cent method. We shall now find a very simple and convenient method for finding interest at six per cent. This method is also useful for finding interest at other rates. 1. What is the interest on $1 at 6% for 1 year? For 1 month? For 1 day? 2. Find the interest on $1 at 6% for 2 years; 5 years; 12 years; 6 years. 3. Find the interest on $1 at 6% for 4 months; 9 months; 10 months; 5 months. 4. Find the interest on $1 at 6% for 12 days; 18 days; 15 days; 20 days; 5 days. 5. Make a rule for finding the interest on $1 at 6% for any number of years; for any number of months; for any number of days. The answer to these questions make clear the following Rule. To find the interest on $1 at 6% for any number of years, months, and days, take 6¢ for every year, for every month, and of a mill for every day. Exercise 54 Find the interest on $1 at 6% for the following periods: 1. 2 yr. 8 mo. 12 da. SOLUTION. $.12+$.04+$.002 2. 3 yr. 2 mo. 18 da. 3. 1 yr. 5 mo. 10 da. 4. 4 yr. 3 mo. 15 da. 5. 7 mo. 20 da. 6. 6 mo. 8 da. 7. 1 yr. 1 mo. 1 da. 8. 25 da. $.162. 9. 5 yr. 25 da. 10. 3 yr. 3 mo. 12 da. 13. 5 mo. 2 da. 14. 9 mo. 20 da. 16. Find the interest on $450 at 6% for 3 yr. 7 mo. 10 da. .18 SOLUTION. The interest on $1 at 6% for 3 yr. 7 mo. 10 da. = $.18+$.035+$.0013 .035 450 .216/ 52. Interest at any given rate by the six per cent method. If the interest on a given sum of money for a given time at 6% is $300, what is the interest at 3%? At 4%? At 5%? At 7%? EXAMPLE. Find the interest on $1250 for 2 yr. 5 mo. 14 1250 The interest on $1250 for 2 yr. 5 mo. 14 da. at 7% = 1×$184.167 6)184.167 = $214.86. 30.695 214.862 Exercise 55 Find the interest on 1. $50 for 3 yr. 5 mo. at 7%. 2. $400 for 7 mo. 12 da. at 5%; at 2%; at 4%. 3. $25.50 for 1 yr. 6 mo. 15 da. at 3%; at 7%. 4. $92.40 for 8 mo. 23 da. at 41%; at 5%. 5. $3000 for 25 da. at 8%. 6. $840 for 2 yr. 24 da. at 5%. 7. $1275.25 for 5 mo. at 4%. 53. Finding the time between two dates. The time for which interest is to be paid is found by computing the time from the date on which the loan was made to the date on which it was paid. This is usually done by subtracting the dates, considering each month to have 30 days. EXAMPLE. For what time should interest be paid on a loan made August 10, 1918, and paid December 4, 1920? SOLUTION. August is the eighth month and December is the twelfth month. Banks, whose loans are usually made for only a short time, count the exact number of days between the dates. EXAMPLE. Find the time from January 6, 1916, to June 19, 1916. SOLUTION. There are remaining in January 25 da., February 29 da., March 31 da., April 30 da., May 31 da., June 19 da. The total number of days is 165. 25 29 31 30 31 19 165 FINDING THE TIME BETWEEN TWO DATES 107 Exercise 56 In the following four exercises find the difference between the two dates by subtraction : 1. January 1, 1919, to May 7, 1920. 2. October 12, 1918, to November 28, 1921. 3. May 23, 1917, to February 5, 1919. 4. August 17, 1918, to May 20, 1920. In the next six exercises find the exact number of days: 5. August 7 to October 21. 6. May 10 to July 14. 7. September 14 to February 19, 1918. 8. February 8 to September 13, 1919. 9. December 12, 1919, to August 6, 1920. 10. May 31 to November 1. 11. Find the interest on $800 at 6% for the exact number of days from June 10 to October 22. 12. Find the interest on $1200 at 6% for the exact number of days from May 12 to July 25. In the remaining exercises find the time by subtracting dates. 13. Find the interest on $875.50 at 7% from January 2, 1912, to October 1, 1915. 14. Find the interest on $680 at 5% from December 19, 1900, to April 5, 1904. 15. Find the interest on $4500 from May 10, 1919, to July 6, 1920, at 7%. 16. Find the interest on $90 from Oct. 23, 1919, to March 6, 1921, at 6%. 17. Find the amount of $750 from Feb. 3 to Nov. 17 at 5%. 54. Promissory notes. When one person borrows money from another the borrower usually gives the lender a written statement of their agreement. Such a statement is called a promissory note. The following is one form of a promissory note : $285,40 Frankville, Idaho, Nov. 1, 19/8. Three years after date..I promise to pay to the order of William fimeson Two Hundred Eighty-five and 100 100 Dollars with interest at 5% per annum from date, for value received. Robert H. Axtell. A promissory note is a written promise to pay a certain sum of money at a certain time. In this note Robert H. Axtell is the maker, William Jameson is the payee, and $285.40 is the face or principal. The date a note is due is called the date of maturity. $450.000 On demand, Macon, Georgia, May 12, 19/9. I promise to pay to the order of Arthur M. Davis-- 00 Four Hundred Fifty and 100 for value received. Dollars Hugo WeKay. A note should state the date, face, the promise to pay, payee, maker, and time to run. If the note bears interest, as in the above example, the rate of interest should be named. |