7. What is the square root of 18? 8. What is the square root of 127 ? Answer, 4.24264, &c. 9. What is the square root of 3857 ? Answer, 62.1047, &c. Answer, 290.3032, &c. 10. What is the square root of 84276? When it is required to extract the square root of a num Application of the Rule of Three; OR SIMPLE PROPORTION. SIMPLE INTEREST. Principal is the money lent. Interest is the money paid for the use of the Principal. Rate per Cent. is a certain sum agreed on between the Lender and the Borrower, for the use of every £100 Principal. Amount is the Principal and Interest added together. Time relates to the years, months, and days for which the Principal is lent. Example. What is the yearly interest of £875. 15s. at £3 per Cent.? £ 8. 100 : 875 15 £ :: 31 By the Directions given in the Rule of Three, the Answer must be Interest, consequently £3 is put for the 3d term. The Answer must be greater; therefore £875. 15s. is put for the 2d term, &c. Multiply by 3. In dividing by 100, retain the units and tens place (65), and cut off the others (30) for the pounds. From the figures retained, the shillings, &c. Example. What is the amount of £1750. 10s. 6d. for 3 years, at £4 per Required the interest of £793. 18s. for 2 yrs. 5 mos. 18 days, at 1. Required the interest of £520. 10s. for a year at 4 per Cent. Answer, £20. 16s. 4 d. 2. What is the interest of £453. 5s. for 3 years, at £5 per Cent. ? Answer, £67. 19s. 9d. 3. What is the amount of £278. 18s. 6d. for 2 years, at £3 per Cent. per annum? Answer, £301. 11s. 9d. 4. Required the interest of 500 guineas for 9 years, at £41 per Cent. Answer, £200. 16s. 3d. 5. What is the interest of £1784. 4s. 8d. for 37 weeks, at £5 per Cent. per annum?* Answer, £63. 9s. 6d. 6. Required the interest of £2745. 11s. 9d. for 125 days, at £31 per Cent.* Answer, £32. 18s. 2d. 7. Required the amount of £494. 12s. 10d. for 41 weeks, at £4 per Cent. Answer, £512. 3s. 10d. 8. What is the interest of £842. 13s. 10d. for 3 yrs. 8 mos. 12 days, at £4 per Cent.? Answer, £124. 14s. 3 d. 9. What is the interest of £532. 15s. from the 4th of March to the 23d of September, both days inclusive, at £3 per Cent.? Answer, £8. 18s. 7 d. 10. Required the amount of £1970. 4s. for 5 yrs. 7 mos. 24 days, at £3 per. Cent. Answer, £2359. 16s. *To find the Interest for weeks, state As 52 weeks given weeks :: interest of 1 year, to the interest required. To find the Interest for days As 365 days given days :: interest for 1 year, to the interest required. COMMISSION AND BROKERAGE. Commission is an allowance of a certain rate per Cent. to a factor or agent, for buying or selling goods for his employer. Brokerage differs from Commission chiefly in the rate being less than £1 per Cent. Example. What is the commission on £978. 15s. 8d., at £2 per Cent.? 1. Required the commission on £427. 18s., at £2 per Cent. Answer, £8. 11s. 13d. 2. Required the commission on £615. 14s. 3d., at £3 per Cent. Answer, £21. 10s. 11 d. |