d. 780 4 9. 3/20 LESSON 4. What is the Interest of 155 dollars for I year, at 24 per cent. ? 155 dol.=15500 cents principal. 2 31000 product. 387150 divided by 100. 387 cents of a cent, In this case annex two ciphers to the dollars, to reduce them into cents, then multiply by 2 and add half the principal to that product. LESSON 5. What is the interest of 231 dollars for 1 year at 3 per cent. ? Ans. 750 cents of the principal to Total, 750/75 divided by 100. Another way by Decimals.-See Card 32. One fourth equals .25; therefore, multiply by 3.25 for the rate per cent. ? [decimals 750175.00 divide by 100 after pointing off the LESSON 6. What is the interest of £8 16 10 for 1 year, at 7 per 7 rate per cent. 10 7 2 one year's intr. 1 half a year's intr. What is the interest of 700 dollars for 3 years and +, at What is the interest of 35 dol. 374 cents for 1 year, at 5 per cent. ? Answer, 176.875 cents. When the rate per cent. is five, divide the principal by 20; the quotient will be the interest for 1 year: this can be easily scanned, because 5 times 20 make 100, and we can have 5 times 20 in 100. 35 dol. 374 cents 3537.5 cents. by 5 and by 4 will be the same as 20. 5)3537.500 principal. 176.875 answer in cents, By this 5 per cent. we can prove any sum of interest of any rate per cent.; for instance, if the rate per cent. be 6, first take one twentieth part of the principal, which quotient will be the interest for one year at 5 per cent. ; then one fifth of that interest added, will make a sum equal to one arising from 6 per cent.; and two-fifths added will make a sum equal to one of 7 per cent., &e. Again, subtract one fifth and we have a sum equal to one of 4 per cent.; subtract two fifths, we have a sum of 3 per cent., &c. &c. This is an easier way to prove sums in interest, than by the Rule of Three. FOR EXAMPLE SEE LESSON 9. What is the interest of 250 dollars for 1 year, at 7 per cent? Answer, 1750 cents. * Decimals annexed. What is the interest of £165 8s. 4d. for 4 years, at 6 per cent. per annum? £165 8 4 principal. d. 4 Answer, £39 14s. 8 5 5 quotient. What is the amount of £35 15 10 for 3 years, at 6 per cent. per annum? Answer, £ 42 4s. 8d. 0.q. £35 15s. 10d. 12 180 42 4 8 0.8 amount. By multiplying the remainder after the 20)190 farthings, by 10, we find the decimal of a farthing. In the above there remained 3; 3 times 10 is 30; 5 in 30? 6 times; this gives .6 of a farthing. 10 20)40 BROKAGE, Is an allowance of a certain number of shillings and pence on every hundred pounds, or of a certain number of cents on every hundred dollars. LESSON 12. Suppose my friend sells goods for me to the amount of £415 16s. 8d. what will his brokage be at the rate of 58. on a hundred pounds? Answer, £1 Os. 9d. 2q. As £100, RULE. is to the rate per cent.; So is the principal, to the brokage required. Reduce the shillings and pence to the decimals of a pound, and annex them to the pounds for a third term. Look at your Rule in Decimals. |