15. $450 at 6% for 1 year; of a year; of a year; 12 years. 16. $600 at 5% for 1 year; of a year; of a year; 11⁄2 years. 17. What part of a year is 6 months? 3 months? 9 months? 4 months? 8 months? 2 months? 10 months? 1 month? 5 months? 7 months? 11 months? 18. What is the interest on $400 at 6% for 6 months? 3 months? 9 months? 4 months? 8 months? 2 months? 10 months? 1 month? 5 months? 7 months? 11 months? Find the interest and the amount of: 19. $800 for 6 months at 5% 20. $600 for 3 months at 8% 21. $900 for 1 month at 4% 22. $600 for 8 months at 3% WRITTEN PROBLEMS 1. What is the interest and the amount of $576 for 2 years 7 months at 5% ? $576, principal .05 $28.80, interest for 1 year 2 (2 years 7 months 2 years) $16.80 57.60 $74.40, interest for 2 years, 7 months 576.00, principal $650.40, amount Find the interest and the amount of: THE ONE-DOLLAR METHOD In computing simple interest a year is generally regarded as 12 months of 30 days each. When the time is given in years, months, and days, or in months and days, the following method may be used: $1 at interest at 6% will earn Find how much $1 will earn at 6% in the following 8. What is the interest on $1 for 2 years 7 months 17 days at 6% ? On $348? 19. Find the interest on $342 for 3 months 10 days at 6%. 20. Find the interest and the amount of $385 for 3 months 20 days at 5%. 21. The interest of any principal at 5 % is what part of the interest at 6% ? 22. What part of the interest at 6 % is the interest at 3%? 4%? 2%? 1%? THE BANKERS' METHOD When the time is given in days, the following method, commonly called the bankers' method, may be used. Since the interest at 6% of any principal for 60 days is .01 of itself, first find the interest for 60 days, and then take such parts of this interest as may be necessary. Thus, in finding the interest at 6% of $360 for 98 days: 98 days $3.60 1.80 = = interest for 60 days interest for 30 days (1 of interest for 60 days) .30 interest for 5 days ( .18 = = interest for 3 days ( $5.88 interest for 98 days = Find the interest at 6% on : of interest for 30 days) of interest for 30 days) 1. How much will $450 earn in 1 year 3 months 2. At 8%, what is the interest on $570 for 1 7 months? year 3. What is the interest on $12,000 for 15 days at 4 %? 4. A man has the use of $1260 for 3 months 21 days. How much interest must he pay if money is worth 5%? 5. What will settle an account of $642 that has been running 54 days, with interest at 7% ? 6. What must be paid to settle in full an account of $945 that has been drawing interest at 5% for 2 months 24 days? 7. How much interest is due Oct. 17 on a note for $ 1485, dated June 26, with interest at 5%? 8. Mr. Davis borrowed $387.54 on Nov. 22, 1910, agreeing to pay 7% interest. He settled the account on May 10, 1911. How much did he pay? 9. On March 12 Mr. Buxton loaned $2800 to Mr. Ray at 5%, interest to be paid every 6 months. When is the first payment due? How much must Mr. Ray pay? 10. How much interest is due Oct. 11, 1911, on a note for $459 that has been running since Jan. 28, 1911, with interest at 8%? 11. Mr. Sampson buys a horse for $156, paying $40 down and agreeing to pay the balance in 3 months with interest at 5%. How much must he pay at the end of the three months? 12. $1740 is borrowed for 20 days at 5%. How much will settle the account at the end of the 20 days? 13. How much is the interest on $750 for 75 days at 4%? 14. Find the interest on $1440 for 48 days at 7%. |