or Truck, is the exchanging of one commodity for another. The word comes from the Spanish baratar, to deceive or circumvent in bargaining, perhaps because those who deal this way usually endeavour to over-reach one another.

To transact properly, the price of one of the commodities, and an equivalent quantity of the other, must be found either by practice, or by the rule of three.

Question 1. How many pounds of cotton, at 9d. per lb. must be given in barter for 13 C. 3 Q. 14. lb. of pepper, at 2 l. 16 s. per C.?

First. Find the price or value of the commodity whose quantity is given as follows:

| C. | Q. | lb. | L. s. | |----|----|-----|------| | 13 | 3 | 14 | 2 | | 26 | | | | | 21 | 10 | 8 | | | 16s.| 1 | 8 | | | 2Q. | | | | | 1Q. | | | | | 14lb.| | | |

L. 38 17

Secondly, Secondly, Find how much cotton, at 9d. per lb., will purchase as under:

| d. | lb. | L. | |----|-----|---| | If 9 : 1 :: 38 17 |

\[ \frac{20}{777} = \frac{12}{9} \]

\[ 9)9324( \quad C. Q. \]

Anf. 1036 lb. = 9

If the above question be wrought decimally, the operation may stand as follows:

| C. | L. | C. | |----|----|----| | If 1 : 2.8 :: 13.875 |

\[ \frac{2.8}{111000} = \frac{27750}{0.0375} \]

\[ 38.8500(1036 = 9) \]

Anf. 37.5

The value or price of the goods received and delivered in barter being always equal, it is obvious that the product of the quantities received and delivered, multiplied in their respective rates, will be equal.

Hence arise a rule which may be used with advantage in working several questions; namely, Multiply the given quantity and rate of the one commodity, and the product divided by the rate of the other commodity quotes the quantity sought; or divided by the quantity quotes the rate.

Quest. 2. How many yards of linen, at 4s. per yard, should I have in barter for 120 yards of velvet, at 15 s. 6 d.?

Yds. Sixp. Sixp. Yds. 120 X 31 = 3720, and 8)3720(459 Anf.