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what must be given for the purchase of 1170 12s. Od. 4 per cent annuities, at 105 per cent P

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Answer, ei229 2 74. suppose I have 1000l, what nominal sum in 3 per cent debentures will it purchase, at 72% per cent? - 72; : 1000 :: 100 2 40 2

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1. Suppose I have 600l, what nominal sum in new 41 per cent debentures will that purchase at 103}l per cent, allowing the broker # per cent on the capital, or sum purchased? 2. What is the purchase of 575l 15s bank stock, at 225l pr.ct? 3. Suppose 4 per cent debentures are 1041 per cent ; what rate of interest do I receive 2 4. Suppose a person has 950l to invest in the 3 per cent consuls, which are, suppose 724 per cent; what sum must he give an order to his broker for, so that including the brokerage, it may exactly cost him the sum he has to lay out? INTEREST,

INTERest is the premium, or money which one person allows to another for the use of any sum of money, for a determinate space of time.

The principal is the money lent.

The rate per cent is a certain sum, agreed upon between the borrower and lender, or determined by the laws of the country in which the parties live, to be paid for the use of every 100l in the principal, for a year.

* The greatest legal interest in England is 51, and in Ireland 61 per cent., but in the colonies belonging to the British dominions, and other countries, a much higher rate of interest is allowed.

The amount, is the principal and its interest added together,

Simple interest is the money arising from the principal only, though such interest remain unpaid any number of years; thus, if the interest of 100l for 1 year, be 5l, it will be 10l for 2 years, and 21 10s. for half a year; Il 5s. 0d. for a quarter of a year, and 8s. 4d. for a month.

Compound Interest is the money arising, not only on the original principal, but also on the interest as it becomes due ; but as it is not legal to charge compound interest on money lent in Ireland, I shall confine myself to

SIMPLE INTEREST.

In Simple Interest, five quantities are concerned, the principal, the rate, the time, the interest and amount ; any three of these being given, except the principal, interest and amount, the other two can be found, Hence, the rule admits of several problems, the most important, and that which will justly claim most attention in what follows, is that in which the principal, the rate and time are given to find the interest and amount ; for resolving this, the following is the *

GENERAL RULE.

As 100 is to the principal, so is the rate per cent, or value paid for the use of 1001, to its interest for 1 year.

As l year is to any other time, so is the interest for 1 year to the interest for that time.

Though this rule is general for all cases of this problem, yet calculations in interest may be much shortened by means of aliquot parts and other devices, which are illustrated in the following cases.

CAse list.—To find the interest of 100l for years at any rate per cent.

Multiply the number of years by the rate per cent, the product is the answer, Črampleń. . 1. What is the interest of 100l for 5 years at 6 per cent?

lyr. : 5yr. :: 6l : 30 the answer, or 5x =30!? 2. What is the interest of 100l for 4 years at 6 per cent : 3. What is the interest of 100l for 33 years at 4 per cent 4. What is the interest of 100l for 7 years at 5 per cent *

Case 2d.—To find the interest of 100l for months at any rate per cent.

As 12 months : given months :: rate : to the interest, or multiply the months by the rate and divide by 12.

If the rate is 6 per cent it is 10s. for each month, therefore half the months will be the interest, to which may be added or subtracted such aliquot part or parts of 6, to or from the inte

rest thus found, as the given rate may be greater or less than six.

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6. What is the interest of 100l for 9 months, at 4% per ct? 7. What is the interest of 100l for 7 months, at 4 per ct? 8. What is the interest of 100l for 11 months, at 7 per ct? Case 3d.—To find the interest of 100l for years and months at any rate per cent. per annum. Make the months the fraction of a year, then multiply the years and fraction thereof, by the rate per cent.

Or may be performed as in the former case.

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9. What is the interest of 100l for 3 years and 5 months, at 5 per cent 2

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10. What is the interest of 100l for 4 years and 3 months, at 6 per cent per annum ?

11. What is the interest of 100l for 6 years and 9 months, at 5 per cent per annum ?

12. What is the interest of 100l for 5 years and 7 months, at 44 per cent per annum ?

13. What is the interest of 100l for 3 years and 4 months, at 7 per cent. per annum ?

14. What is the interest of 100l for 8 years and 2 months at 5% per cent per annum ?

Case 4th.--To find the interest of any sum for one year, at any rate per cent per annum.

Multiply the given sum by the rate, and divide the produet by 100. Or, if the rate is an aliquot part of 100, divide the given principal by the denominator of such aliquot part; but where there are more parts than one, in the given rate, the former rule is preferable. Čramples.

15. What is the interest of 325l 12s. 6d. for one year, at per cent per annum ?

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16. What is the interest of 460l 15s for 1 year at 64 per ct

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17. What is the interest of 460l 15s for 1 year at 54 * ct 18. What is the interest of 741. 12s 6d for 1 yr at 5% + ct 19. What is the interest of 893, 16s 8d for 1 yr at 44 to ct

Find the interests of the following sums for 1 year at the given rates per cent per annum?

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CASE 5th.--To find the interest of any sum for years and months, at any rate per cent. '

Find the interest of 100l for the given time, per case 3d. and take such parts of the given sum, as the interest found may be of 100l, and the quotient or sum of the quotient, arising from dividing the given number by denominator or denomimators of the aliquot part or parts will be the interest required.

Where there are fractions thus produced, it will be best to find the interest of the given sum for 1 year, which multiply by the number of years, and add proportionably for the months.

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30. What is the interest of 4691 10s. for 2 years and 3 months, at 6 per cent per annum ?

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