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What is the interest of 40 dollars for ten days Ans. 10 are $ 6)40

6,4 cents. What is the interest of 12 dollars for 20 days? Ans. 20 are

12
2

6)24

Ans. 4 cents

Note.-The scholar will recollect his rule, that to multiply by a fraction, division is necessary, and when the numerator is 19 division alone is necessary.

The longest of the remaining sums in this rule may be performed on the slate at recitation.

What is the interest of 120 dols. for 8 years, 4 months, and 15 days.

120
501 half the number of

months.
6000

30

Ans. $60, 30 Where did you get the ! Ins, 15 are ; of is

What is the interest of 60 dols. for 16 years S months and 10 days.

6)60,00 annexing 2 cyphers for

10 multipiying by the

number of months.

Ans. $60,10 The ten is thus placed because 60 only is to be mul.. tiplied by

What is the interest of 12 dollars for 41 years 8 months and 25 days?

12

12 250 13

25 are = double of 6 makes 1.2i.e.

12 60

600 24

5

Ans. 30,05 What is the interest of 100 dollars for 15 days? Ans. 25 cents.

What is the interest of 24 dollars for of a month? Ans. 4 cents.

To give as difficult a sum perhaps, as any, to show the conciseness of the rule; what is the interest of 1200 dols. for 12 years, 11 months and 29 days? 1200

1200 29

10800

8400 2400

8400

600 6,0)3480,0

580 580 $ 935,80 with į the usual num

ber of figures. To cast the interest when the rate is not 6 what do first? Ans. Find the interest as before, for 6

per cent.

What do then? Ans. Multiply by the given rate and divide by 6.

EXAMPLES. What is the interest of 120 dollars for 15 years, 11 months and 25 days at 9 per ceut..

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1,15,10 for 6 per cent, and about as many

9 figures as in the usual mode of this

per cent.

6)103590

$172,65 Ans. with 47 figures. There being a saving of 16 figures by the new

method, and not so difficult 10 be understood, and practised by the scholar, as by the old way of taking parts.

Note.-When no months or days enter into the calculation, the old method of multiplying by the rate and then by the years is evidently, preferablo for the adept, but experience has proved, that one uniform way is better than to perplex the novice with two rules totally different in their operations, wheu one in all cases will solve his questions.

What is the interest of 30 dols. for 2 days at 3 per cent? Ans. 36)30

;01

3

603

,005 mill.

What the interest of 12 dols. for 10 days at 5 per cent?

What is the interest of 60 dols. for 5 days at 4

per cent?

What is the interest of 40 dols. for 3 days at 12

per cent?

What is the interest of 40 dols. for 3 days at 123

per cent?

What is the interest of £100 for one year 8 months and 9 days, at 8 per

cent?

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720 Ans. £13 10s. 7d. On what principle do you multiply by the given rate, and divide by 6? Ans. On the principal of the Rule of Three.

What would be the statement? Ans. If 6 per cent, draw so much interest, what will the given rate draw.

Why multiply by the number of months? Ans. Because a dollar drawshalf a cent a month.

COMMISSION. What is an allowance made to persons, in buying and selling goods for others called? Ans. Commission.

How are questions in this rule, Brokerage and Insurance answered ? Ans. By Interest.

What do you demand for selling 400 dollars worth of Cotton, at 21 per cent commission? Ains. $10.

What is your demand for selling 300 pounds of

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