CHAPTER XII. SIMPLE AND COMPOUND INTEREST. - DISCOUNT. — CAUSE AND EFFECT. — PARTNERSHIP.- BONDS AND STOCKS. TO FIND PRINCIPAL, RATE, OR TIME. 931. At what rate per cent will $723.60 amount to $759.78 in 1 yr. 1 mo. 10 da. ? 932. In what time will $85.50 produce $8.17 interest, at 4 per cent? 933. Slate Exercises. Find rate, time, etc. 1. Principal, $2,000; time, 3 yr.; interest, $300. Rate? 2. Principal, $1,800; rate, 4%; interest, $144. Time? 3. Time, 8 mo.; rate, 41%; interest, $2.88. Principal? 4. Principal, $38; time, 2 yr.; amount, $40.28. Rate? 5. Principal, $140; rate, 3%; time, 3 mo. 15 da. Interest? 6. Amount, $39.60; rate, 4%; time, 2 yr. 6 mo. Principal? 7. Amount, $484.15; rate, 31%; principal, $460. Time? 8. Principal, $39.60; rate, 4%; time, 1 yr. 7 mo. 15 da. Amount? 9. Time, 8 yr.; rate, 3%; amount, $6,200. Principal ? 10. Principal, $7,548; time, 3 mo. 5 da.; interest, $119.51. Rate? 11. Principal, $9,000; rate, 4%; interest, $632. Time? 12. Time, 2 yr. 3 mo. 20 da.; rate, 5%; amount, $160.60. Principal? 13. Principal, $756; rate, 31%; time, 3 yr. 4 mo. 20 da. Interest? 14. Principal, $120; time, 1 yr. 2 mo. 15 da.; interest, $4.35. Rate? 15. Amount, $97.57; rate, 4%; interest, $7.57. Time? 16. Time, 3 yr. 8 mo. 19 da; rate, 41%; amount, $93.39. Principal? 17. Principal, $1,848; rate, 33%; time, 4 yr. 9 mo. 25 da. Amount? 18. Rate, 5%; time, 4 yr. 6 mo. 23 da.; interest, $16.43 Principal? 934. Oral Exercises. 1. In what time will $100 amount to $109, at 6% interest? 2. At what rate will $200 produce $16 interest in 2 years? 3. What principal will produce $ 12 interest in 3 years, at 4%? 4. In what time will $300, at 4%, produce $29 interest? 5. In what time will $170 produce $1.70 interest, at 5%? 6. In what time will $360 produce $3.60 interest, at 4%? 7. In what time will $725 produce $7.25 interest, at 6%? 8. In what time will $45 produce 45¢ interest, at 41%? 9. In what time will $72 produce $1.44 interest, at 6%? 10. Find the interest on $84 for 144 days, at 5%. 11. Find the interest on $125, at 5%, for 2 months 12 days. 12. At what rate will $64 produce 64 interest in 80 days? 13. At what rate will $40 produce $1.20 interest in 6 months? 14. A certain principal produces $120 interest, at 6%. What would be the interest if the rate were 4%? INTEREST BY ALIQUOT PARTS. 936. Slate Exercises. 1. Find the interest on $387.45, for 2 yr. 8 mo. 18 da., at 7%. $387.45 x .07. $27.1215 interest for 1 year. 27.1215 interest for 1 year. 1.1301 interest for 15 days. .2260 interest for 3 days. 2. Find the interest on $432.90, at 6%, for 1 yr. 7 mo. 12 da 3. Find the amount of $874.16, at 5%, for 1 yr. 9 mo. 4 da. 4. What is the amount of $95.72, for 3 yr. 6 mo. 20 da., at 5. Interest of $1,806.45, at 4%, for 1 yr. 7 mo. 25 da. 1 yr., 6 mo., 1 mo., 15 da., 5 da., 5 da. 6. Interest for 10 mo. 29 da., at 4%, on $380.40. 7. Amount, at 6%, of $125.73, for 2 yr. 10 mo. 4 da. 8. Interest on $84.66, at 7%, for 1 yr. 4 mo. 12 da. 9. Interest, at 5%, for 4 yr. 2 mo. 7 da., on $250. 10. Amount of $1,000, at 6%, for 33 days. 937. When the time is less than a year, the following facts should be remembered: 6% for a year is 1 per cent for 60 days. 11. Find the interest for 81 days, at 5%, on $876.40. 12. Amount of $954, at 4%, for 4 mo. 10 da. 13. Interest of $1,874, at 41%, for 93 days. 80 days = 1%. 10 days 2 days 1 day 14. Interest of $753.20, at 5%, for 158 days. 72 da., 72 da., 12 da., 2 da. 15. Amount of $1,234.50, for 193 days, at 6%. 60 da., 120 da., 12 da., 1 da. |