17. At 7 per cent., for 8 months 10 days, what part of the principal will equal the interest?

18. At 6 per cent., for 5 years 7 months and 15 days, what part of the principal will equal the interest?

19. At 8 per cent., for 3 years 5 months and 12 days, what part of the principal equals the interest?

20. At 7 per cent., for 11 months 3 days, what part of the principal will equal the interest?

21. At 4 per cent., for 8 years 6 months and 15 days, what part of the principal will equal the interest?

89. 1. What is the interest of $40 for 3 years 4 months, at 6 per cent.?

ANALYSIS. 3 years 4 months equals 34, or years; and the interest of any sum for years, at 6 per cent., equals of it. (88.) f of $40 is $8, the required interest. Therefore, &c.

Or thus: Since the interest of $1 for 1 year, at 6 per cent., is 6 cents, for $40 it is 40 times 6 cents, or $2.40, and for 3 years it is 34 times $2.40, equal to $8.

2. What is the interest of $150 for 2 years 10 months, at 8 per cent.?

3. What is the interest of $80.40 for 4 years 2

months, at 7 per cent.?

4. What is the interest of $240 for 1 year 9

months, at 5 per cent.?

5. What is the interest of $120 for 5 years 8

months, at 7 per cent.?

6. What is the interest of $90 for 4 years 7 months, at 4 per cent.?

7. What is the interest of $500 for 10 months, at 6 per cent. ?

8. What is the interest of $128 for 2 years 9 months, at 64 per cent.?

9. What is the interest of $125 for 1 year 4 months, at 7 per cent.?

10. What is the interest of $300 for 8 months, at 6 per cent.?

11. What is the interest of $50 for 5 years 7 months and 15 days, at 8 per cent.?

ANALYSIS. The interest of any sum for 5 years 7 months and 15 days, at 8 per cent., equals 25 of it, (88, Ex. 12;) 20 of $50 is $24, and 2 of $50 is 9 times $24, equal to $22. Therefore, &c.

12. What is the interest of $75.60 for 4 years 5 months and 10 days, at 9 per cent.?

13. What is the interest of $50 for 6 years 4 months and 24 days, at 5 per cent.?

14. What is the interest of $300 for 4 years 7 months and 15 days, at 8 per cent.?

15. What is the interest of $288 for 8 months 10 days, at 7 per cent.?

16. What is the interest of $1200 for 20 days, at 6 per cent. ?

17. What is the interest of $40 for 9 months 5 days, at 4 per cent.?

18. What is the interest of $36.72 for 5 years 6 months and 20 days, at 7 per cent.?

19. What is the interest of $120 for 2 years 1 month and 6 days, at 125 per cent.?

20. What is the interest of $24 for 11 months and 20 days, at 15 per cent.?

21. What is the interest of $2000 for 18 days, at 5 per cent.?

22. What is the interest of $1500 for 2 months and 24 days, at 6 per cent.?

90. 1. What will be the amount of $60 for 2 years 6 months, at 6 per cent.?

ANALYSIS. Since the interest is equal to 28 of the principal, (88,) and the amount is equal to the principal and interest, it follows that, the principal, added to, the interest, equals, the amount. 2 of $60 is $3, and of $60 is 23 times $3, or $69, the amount. Therefore, &c.

NOTE, When more convenient, the interest may first be found, to which add the principal, and the result will be the amount.

2. What is the amount of $36 for 4 years 2 months, at 7 per cent.?

3. What will $120 amount to in 2 years 11

months, at 8 per cent.?

4. What will $96.48 amount to in 3 years 4

months, at 64 per cent.?

5. What will $80.50 amount to in 6 years 8 months, at 45 per cent.?

6. What will $20.25 amount to in 12 years, at 5 per cent.?

7. What will $1500 amount to in 10 months, at 10 per cent.?

8. What will $150 amount to in 6 months and 20 days, at 6 per cent.?

9. What will $250 amount to in 9 months and 18 days, at 7 per cent.?

10. What is the amount of $480 for 1 year 10 months and 25 days, at 5 per cent. ?

11. What is the amount of $500 for 3 years 4 months and 24 days, at 6 per cent.?

12. What is the amount of $240 for 2 years 7 months and 6 days, at 7 per cent.?

13. What is the amount of $1000 for 5 years 1 month and 6 days, at 4 per cent.?

14. What is the amount of $120 for 10 years 6 months and 20 days, at 3 per cent.?

91. 1. What principal in 3 years 9 months, at

8 per cent., will give $90 interest?

of

ANALYSIS. Since the interest for 3 years 9 months, at 8 per cent., is & of the principal, (88,) $90 must be the required principal. Since $90 is to, to is & of $90, or $30, and $30 is to of 10 times $30, or $300, the principal. Therefore, &c.

2. What principal, in 1 year 8 months, at 9 per cent., will give $36 interest?

3. What principal in 11 months, at 6 per cent., will give $22 interest?

4. What principal in 7 months 15 days, at 8 per cent., will give $40 interest?

5. A rents a store to B for the yearly rent of $300, which is 12 per cent. of its cost; what did it cost?

6. A gentleman bought 6 horses, for which he paid a sum of money which in 2 years 6 months, at 4 per cent., would have given him $90 interest; what did he pay apiece for the horses?

7. A person deposits of his money in the bank, which brings him an annual income of $1500, at 10 per cent.; the remaining he invests in business which yields him 20 per cent. profit; what are his entire capital and his yearly income?

and 4

8. Two persons engaged in trade; A furnished of the capital, and B; at the end of 3 years months they found that they had made a clear profit of $5000, which is 124 per cent. per annum on the money invested; how much capital did each furnish ?

9. A capitalist invested of his money in railroad stock, which depreciated 5 per cent. in value; the remaining he invested in bank stock, which at the end of 1 year had gained $1200, which was 12 per cent. of the investment; what was the whole amount of his capital, and what was his entire loss or gain?

92. 1. What principal will, in 3 years 4 months, at 5 per cent, amount to $700.

ANALYSIS. Since the interest for 3 years 4 months, at 5 per cent., is & of the principal, (88,) the principal, added to the interest, equals the amount; hence $700 is f of the principal. Since $700 is z, & is + of $700, or $100, and $100 is & of 6 times $100, or $600. Therefore, &c.

2. What principal in 5 years, at 6 per cent., will amount to $1300?

3. What principal in 1 year 6 months, at 8 per cent., will amount to $280?

4. What principal in 4 years 2 months, at 3 per cent., will amount to $630?

5. What principal in 10 years, at 7 per cent., will amount to $340?

6. What principal in 9 months, at 10 per cent., will amount to $172?

7. What principal in 18 months, at 4 per cent., will amount to $530?

8. The amount due on a bond and mortgage is $2900, it having been on interest 7 years 6 months, at 6 per cent.; what was the principal?

9. Two men bought 200 acres of land, and at the end of 2 years sold it for $1500, which was an advance of 12 per cent. per annum on its cost; what did it cost an acre?

10. A man invested of all he was worth in the lumber trade, and at the end of 2 years 8 months sold out his entire interest for $3100, which was a yearly gain of 9 per cent. on the money invested; how much was he worth when he commenced trade ?

11. A's money is to B's as 2 to 3; if of A's money be put at interest for 3 years 9 months, at 10 per cent., it will amount to $550; how much money has each?