4. What may a broker demand, when he sells goods to the value of 508l. 175. 10d. and I allow him 14 per cent ? Ans. £7 12s. 8d. : INSURANCE, IS a premium at so much per cent. allowed to persons and offices, for making good the loss of ships, houses, merchandize, &c. which may happen from storms, fire, &c. EXAMPLES. 1. What is the insurance of 725l. 8s. 10d. at 124 per cent. ? Ans. £90 135. 7.d. 2. What is the insurance of an East-India ship and cargo, valued at 123425 dollars, at 155 per cent. ? Ans. $19130, 87cts. 5m. 3. A man's house estimated at 3500 dollars, was insu. red against fire, for 18 per cent. a year : what insurance did he annually pay ? Ans. $61, 25cts. SHORT PRACTICAL RULES, or months and days. RULE. 1. If the principal consists of pounds only, cut off the unit figure, and as it then stands it will be the interest for one month, in shillings and decimal parts. 2. If the principal consists of pounds, shillings, &c. reduce it to its decimal value; then remove the decimal point one place, or figure, further towards the left hand, and as the decimal then stands, it will shew the interest for one month, in shillings, and decimals of a shilling. 1. Required the interest of 541. for seven months and ten days, at 6 per cent 10 days=4)5,4 Interest for one month. 37,8 ditto for 7 months. Ans. 39,6 shillings=£1 19s. 7,200 12 2. What is the interest of 421. 10s. for 11 months, at 6 per cent. : k. S. £. 42,5 decimal value. 11 £. s. d. Ans. 46,75 Interest for 11 mo.= 2 6 9 3. Required the interest of 941. 78. 6d. for one year, five months and a half, at 6 per cent. per annum. Ans. £8 5s. 1d. 5,5qrs. 4. What is the interest of 121. 13s. for one third of a month, at 6 per cent. : Ans. 5,161. II. FOR FEDERAL MONEY. RULE. 1. Divide the principal by placing the separatrix as usual, and the quotient will be the interest for one month in cents, and decimals of a cent; that is, tke figures at the left of the separatris will be cents, and those on the right, decimals of a cent. 2. Multiply the interest of one month by the given number of months, or morths, and decimal parts thereof, or for the days take the even parts of a month, &c. EXAMPLES. 1. What is the interest of 341 dols. 52 cts. for 7 1-% months ? 2)341,52 Or thus, 170,76 Int. for one montth:. 170,76 Int. for one month. 7,5 months. 71-2 85380 1195,32 do. for 7 mo. 119532 85,38 do. for 1-2-mo. $ cts. M. 1280,700cts.=12.80 7 1280,70 Ans. 1280,7cts.=$12, 80cts. 7m. 2. Required the interest of 10 dols. 44 ets. for three years, 5 months and 10 days. 2)10,44 215,76cts. Ans.=$2, 15cts. lim. 23. What is the interest of 342 dollars for 11 months ! The 1-2 is 171 Interest for 1 month. 11 Ans. 1881cts.=$18, 81cts. Note.--To find the interest of any sum for 2 months, at 6 per cent, you need only call the dollars so many cents, and the inferior denominations decimals of a cent, and it is done: Thus, the interest of 100 dollars for two months, is 100 cents, or 1 dol. lar; and $25,40 ets. is 25 cts. 4m. &c. which gives the following RULE II. Multiply the principal by half the number of months, and the product will show the interest for the given time, in cents and decimals of a cent, as above. EXAMPLES. 1. Required the interest of 316 dollars for 1 year and 10 months. 11-half the number of mo Ans. 3476cts.=834, 76cts. 2. Whatıs the interest of 364 dols. 25cts. for 4 months? 8 cts. 364, 25 2 half the months. 728, 50cts. Alts.=87, 28cts. 5m. III. When the principal is given in federal moncy, at 6 par cent. to find how much the monthly interest will be in New-England, &c. currency. RULE. Multiply the given princival by ,03 and the product will be the interest for one incunth, in shillings and decimal parts of a shilling. EXAMPLES. 1. What is the interest of 525 dols. for 11 months ? ,03 3,75 shil. int. for 1 month. x11 months. Ans. 107,255.=5578. 3d. 2. What is the interest in New-England currency, of 31 dols. 68 cts. for 5 months ? Principal 31,68 dols. ,03 ,9504 Interest for one month, 5 Ans. 4,7520s.=4s. 9d.' 12 IV. When the principal is yiven in pounds, shillings, &c. New-England currency, at 6 per cent. to find how inuch the monthly interest will be in federal money. RULE. Multiply the pounds, &c. by '5, and divide that product by 3, the quotient will be the interest for one munth, in cents, and decimals of a cent, &c. EXAMPLES. 1. A note for £411 New-England currency has been on interest one month; how much is the interest thereof 'n federal money! £o 411 5 3) 2055 Ans. 685cts.=S6, 85cts. S. Required the interest of 396. 185. N. E. currency for 7 months ? 39, 5 3:6,9 decimal value. Vitto for 7 months, 465,5cts.=-84, 65cts. 51. Ans. V. When the principal is given in New-England and Virginia currency, at 6 per cent. to find the interest for a year, in dollars, cents and inills, by inspection. RULE. Since the interest of a year will br, just so many cents as the given principal contains shillings, therefore, write Jown the shillings and call them cents, and the pence in the principal made less by 1 if they exceed 3, or by 2 when they exceed 9, will be the mille, very nearly. |