22. What is the interest of $160 for 3 years, 4 months and 9 days, at 6 per cent.? At 5 per cent.? At 8 per cent.? At 7 per cent.?

23. What is the interest of $200 for 2 years, 6 months and 15 days, at 4 per cent.? At 6 per cent.?

24. The interest of $240 for a certain time is $18, at 6 per cent.; how much is it at 8 per cent.? 25. The interest of $225 for 4 years is $54; what is the interest for 1 year?

For 2 months? For 1 month?

For 3 months?

26. The interest of $120 for 1 year is $7.20; how much is it for 4 months? For 2 months? For 1 month and 10 days? For 20 days?

LESSON XLV.

1. What is the amount of $40 for 2 years, at 6 per cent.?

NOTE. The amount is the sum at interest, or the principal, and the interest taken together. The interest on $40 for 2 years, at 6 per cent. $4.80; and $40+$4.80 $44.80, the amount.

=

2. What is the amount of $60 for 4 years, at 4 per cent.?

3. What is the amount of $80 for 3 years, at 5 per cent.?

4. What is the amount of $100 for 6 years, at 4 per cent.?

5. What is the interest of $70 for 6 years, at 7 per cent.?

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6. What is the amount of $125 for 2 years, at per cent.?

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

8. What is the interest of $25 for 6 years and 1 month, at 6 per cent.?

9. What is the interest of $10 for 4 years and 2 months, at 7 per cent.?

10. What is the amount of $150 for 4 years and 1 month, at 7 per cent.?

11. Required the amount of $200 for 2 years and 2 months, at 4 per cent.

12. Required the amount of $145 for 6 years and 3 months, at 8 per cent.

13. Required the amount of $400, at 3 per cent., for 2 years, 2 months and 20 days.

14. What is the amount of $140 for 5 years, 4 months and 10 days, at 7 per cent.?

15. What is the amount of $200 for 2 years, 6 months and 14 days, at 6 per cent.?

16. What is the interest of $15 for 6 years, 4 months and 2 days, at 8 per cent.?

17. What is the amount of $360 for 8 years, 2 months and 12 days, at 6 per cent.?

18. What is the amount of $180 for 6 years, 7 months and 13 days, at 7 per cent.?

19. What is the amount of $200 for 5 years and 9 months, at 4 per cent.?

20. What is the amount of $140 for 3 years, months and 18 days, at 8 per cent.?

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21. What is the amount of $175 for 4 years, 4 months and 9 days, at 6 per cent.?

22. What is the amount of $140 for 3 years, 6 months and 18 days, at 3 per cent.?

23. Required the amount of $160 for 9 years, at 5 per cent.

24. Required the amount of $300 for 5 years, 8 months and 6 days, at 6 per cent.

25. What is the amount of $250 for 3 years, 6 months and 24 days, at 7 per cent.?

26. What is the amount of $500 for 1 year, 5 months and 20 days, at 10 per cent.?

LESSON XLVI.

1. If the interest of $120 for 1 year is $9, what is the interest of $60? Of $20? Of $10?

2. If the interest of $400 for 1 year is $24, what is the interest of $100? Of $10? Of $1? 3. If the interest of $12 for 5 years is $3.60, what is the interest of $6? Of $60? Of $300? 4. If the interest of $160 for 2 years is $18, what is the interest of $80? Of $40? 5. If the interest of $280 what is the interest of $70? 6. If the interest of $100 what will it be for 6 years? 4 years? For 1 year?

for 3 years is $46, Of $140?

for 3 years is $20, For 10 years? For

7. If the interest of $180 for 2 years is $23, what is it for 3 years? For 7 years? For 1 year?

8. If the interest of $200 for 3 years is $27, what is its interest for 1 year? For 1 month? For 4 months? For 7 months?

9. If the interest of $200 for 1 month is $1, what is it for 15 days? For 5 days? For 1 day? 10. If the interest of $140 for 1 year and 4 months is $10, what is it for 8 months? For 4 months? For 2 months? For 1 month?

11. The interest of $240, at 6 per cent., is $27; what is it at 3 per cent.? At 1 per cent.?

12. The interest of $320, at 7 per cent., is $15; what is it at 1 per cent.? At 8 per cent.?

13. If the interest of $100 for 3 years is $21, what is the rate per cent.?

14. If the interest of $300 for 1 year is $21, what is the rate per cent.?

15. What is the interest of $100 for 4 years, at 1 per cent.? If the interest of $100 for 4 years is $20, what is the rate per cent.?

16. If the interest of $300 for 2 years is $48, what is the rate per cent.?

NOTE. Since the interest of $300 for 2 years, at 1 per cent., is $6, $48 will be as many per cent. as $48 contains times $6.

17. If the interest of $200 for 2 years is $12, what is the rate per cent.?

18. If the interest of $400 for 3 years is $24, what is the rate per cent.?

19. If the interest of $150 for 3 years and 4 months is $35, what is the rate per cent.?

20. If the interest of $25 for 1 year and 8 months is $1, what is the rate per cent.?

NOTE. The interest of $25 for 1 year and 8 months, at 1 per cent., is 13 times Too of $25=ʊ of $25-$1, and the rate per cent. required will be as many per cent. as $ is contained times in $1, which are 22 times. Therefore, 2 per cent. is the answer.

21. If the interest of $50 for 1 year and 3 months is $3, what is the rate per cent.?

22. If the interest of $75 for 4 years and 2 months is $12, what is the rate per cent.?

23. A man paid $8 for the use of $48 for 1 year and 4 months; what was the rate per cent.?

24. John Niles lends Harry Hubbard $30 for 2 years and 6 months; Harry has to pay at the end of the time $36; what is the rate per cent.?

NOTE.The principal, $30, has to be paid back, and is of course a part of the $36; the remainder, $6, is the interest, by which the rate per cent. is to be found.

25. A note of $100, being on interest 2 years and 2 months, amounted to $125; what was the rate per cent.?

26. A gentleman lent $60 for 1 year and 6 months, and received $90; what was the rate per cent.?

LESSON XLVII.

1. What principal, at 10 per cent., is sufficient to gain $6 in 4 years?

NOTE. Since the interest of $1 for 4 years, at 10 per cent., is 40 cents, $6 is the interest of as many dollars as 40 cents or 4 dimes is contained times in $6 or 60 dimes, which are 15; therefore, $15 is the answer.

2. What principal, at 4 per cent., is sufficient in 2 years to gain $8?

3. What is the principal that, in 4 years, at 3 per cent., will gain $6?

4. What principal, at 6 per cent., is sufficient in 5 years to gain $10?

5. What principal is sufficient in 2 years and 4 months, at 4 per cent., to gain $64?

6. What principal is sufficient in 2 years, at 8 per cent., to gain $10?

7. What principal is sufficient in 6 years, at 1 per cent., to gain $20?

8. What principal, at 4 per cent., in 1 year and 7 months, will gain $5?

9. What principal, in 6 years and 4 months, at 6 per cent., will gain $18?

10. What principal is sufficient in 7 years to gain $18, at 7 per cent.?

11. The interest on a note for 4 years and 2 months, at 4 per cent., was $60; what was the principal?

12. If the interest of $50, at 6 per cent., is $6, how long was it on interest?

NOTE. Since $50 at 6 per cent. will require 1 year to gain $3, it will require as many years to gain $6 as $3 is contained times in $6, which are 2 times. Therefore, 2 years is the an

swer.