21. If 3 men can do a piece of work in twelve days, in how many days will 4 men do the same work?

22. If 2 cocks of a certain size will empty a cistern in 6 hours, in how long a time will 3 cocks of the same size empty it?

23. Three men, setting out on a journey, purchased 5 loaves of bread apiece, but before they had caten any of it, two other men joined them, and they agreed to share the bread equally among the whole; how many loaves did they have apiece?

24. If 4 barrels of flour cost twenty-four dollars, what would 7 barrels cost? How much cider at 3 dollars a barrel would 7 barrels of flour buy?

25. A man bought a quantity of flour for fiftyfour dollars; and another man gave him 9 yards of cloth for 5 sixths of it; what was the cloth worth a yard?

26. If 9 yards of cloth cost fifty-four dollars, how many boxes of butter, at 4 dollars a box, would 5 yards of the same cloth buy?

27. Bought 8 firkins of butter for seventy-two dollars, and gave 6 of them for 7 yards of cloth; what was a yard of the cloth worth?

28. A man bought 6 barrels of flour for sixty dollars, and gave 4 barrels of it for cider at 5 dollars a barrel; how many barrels did he buy?

Note. The manner of writing numbers with figures has been explained as far as ten. The numbers from ten to one hundred are written as follows:

A. 1. BOUGHT 1 half of a yard of cloth for 1 shilling, what would be the price of a yard at the same rate?

2. If 1 half pint of cherries cost 2 cents, what will a pint cost?

3. If 1 fourth of a barrel of flour cost 2 dollars, what would a barrel cost?

4. 2 is 1 half of what number? 1 fourth of what number?

5. If 1 third of a yard of cloth cost 2 dollars, what is that a yard?

6. 2 is 1 third of what number?

7. If 1 third of a yard of cloth cost 3 dollars, what is that a yard?

8. 3 is 1 third of what number?

9. If 1 fourth of a firkin of butter cost 3 dollars, what is that a firkin?

10. 3 is 1 fourth of what number?

11. A man bought 1 third of a bushel of wheat for 4 shillings, what would a bushel cost at that rate?

12. 4 is 1 third of what number?

13. If a man can ride 2 miles in 1 fifth of an hour, how far can he ride in an hour?

14. 2 is 1 fifth of what number?

15. A man, being asked the age of his eldest son, answered that his youngest son, who was 3 years old, was just 1 fifth of the age of his eldest son; how old was the eldest son?

16. 3 is 1 fifth of what number?

17. A man bought 1 sixth part of a hundred weight of sugar for 2 dollars, what would a hundred weight cost at the same rate?

18. 2 is 1 sixth of what number?

19. Bought 1 fifth of a pound of starch for 5 cents, what was that a pound?

20. 5 is 1 fifth of what number?

21. Bought 1 fourth of a pound of aquafortis for 6 cents, what was that a pound?

22. 6 is 1 fourth of what number?

23. Bought 1 seventh of a hundred weight of cocoa for 4 dollars, what would 1 hundred weight cost at the same rate?

24. 4 is 1 seventh of what number?

25. 7 is 1 fifth of what number?

26. 5 is 1 third of what number?

27. 4 is 1 cighth of what number? 28. 6 is 1 sixth of what number? 29. 8 is 1 third of what number? 30. 9 is 1 fourth of what number? 31. 7 is 1 sixth of what number? 32. 8 is 1 seventh of what number? 33. 9 is 1 eighth of what number? 34. 8 is 1 tenth of what number? 35. 7 is 1 ninth of what number? 36. 6 is 1 fifth of what number?

37. 10 is 1 seventh of what number?

B. 1. A man bought some linen and some cotton cloth, for the linen he gave 4 shillings a yard, which was twice as much as he gave for the cotton; what did he give for a yard of the cotton?

2. 4 is 2 times what number?

3. If 2 thirds of a yard of cloth cost 6 dollars, what would 1 third cost?

4. 6 is 2 times what number?

5. If 3 fourths of a barrel of flour cost 6 dollars, what will one fourth of a barrel cost?

6. 6 is three times what number?

7. If 2 fifths of a pound of chocolate cost 8 cents, what would 1 fifth of a pound cost?

8. 8 is 2 times what number?

9. If 3 fifths of a pound of candles cost 9 cents, what will 1 fifth of a pound cost?

10. 9 is 3 times what number?

11. If 2 sevenths of a pound of spermaccti candles cost 10 cents, what will 1 seventh of a pound cost?

12. 10 is 2 times what number?

13. If 5 eighths of a pound of cotton cost 10 cents, what will 1 eighth cost?

14. 10 is 5 times what number?

15. If 2 thirds of a yard of cloth cost 4 dollars,

what will 1 third cost? If 1 third of a yard cost 2 dollars, what will a yard cóst ?*

16. If 4 is 2 thirds of some number, what is 1 third of the same number? 2 is 1 third of what number ?*-Then 4 is 2 thirds of what?

17. If 2 thirds of a barrel of flour cost 6 dollars, what will third of a barrel cost? If 1 third of a barrel cost 3 dollars, what will a barrel cost ?*

18. If 6 is 2 thirds of some number, what is 1 third of the same number?-3 is 1 third of what number?-Then 6 is 2 thirds of what?

19. If 3 fourths of a bushel of wheat cost 6 shillings, what will 1 fourth of a bushel cost? If 1 fourth of a bushel cost 2 shillings, what will a bushel cost?

20. If 6 is 3 fourths of some number, what is 1 fourth of the same number?-2 is 1 fourth of what number ?-Then 6 is 3 fourths of what?

21. If 2 fifths of a gallon of wine cost 4 shillings, what will 1 fifth of a gallon cost? If 1 fifth of a gallon cost 2 shillings, what will a gallon cost?

22. If 4 is 2 fifths of some number, what is 1 fifth of the same number? 2 is 1 fifth of what number? -Then 4 is 2 fifths of what?

23. If 3 sevenths of a pound of tobacco cost 6 cents, what will 1 seventh of a pound cost? If 1 seventh of a pound cost 2 cents, what will a pound cost?

24. If 6 is 3 sevenths of some number, what is 1 seventh of the same number ?-2 is 1 seventh of what number?-Then 6 is 3 sevenths of what?

25. If 2 sevenths of a barrel of fish cost 4 dollars, what will 1 seventh of a barrel cost? What will a barrel cost?

26. 4 is 2 sevenths of what number?

27. If 3 eighths of a pound of chocolate cost 6

* See this section, article A.