XlS ARITHMETIC. 



48. A legiment of soldiers, consisting of 976 menj^are 

 to be new clothed, each coat to contain 2-f yards of cloth 

 that is i|-yd. wide, and to be lined -v^ith shalloon |-yd. wide } 

 how many yards of shalloon will line them ? 



Ans. 45 3 J yds. iqr. 2—^1 



PRACTICE. 



Practice is a contraction of the rule of three, when 

 the first term happens to be an unit, or one ; and has its 

 name from its daily use among merchants and tradesmen, 

 being an easy and concise method of working most quest- 

 ions, that occur in trade and business. 



The method of proof is by the rule of three. 



An aliquot .part of any number is such a part of it, as, 

 being taken a certain number of times, exactly makes that 

 number. 



GENERAL RULE.* 



I. Suppose the price of the given quantity to be iJ. is. 

 or id. as is most convenient ; then will the quantity itself 

 be the answer, at the supposed price. 



2. Divide 



* The rule, and its application to the following particular 

 Cases, will be rendered very evident by an explanation of the ex- 

 ample. In this example it is plain, that the quantity 526 is the 

 ansu'cr at il. consequently, as 3s. 4d. is the -g- of il. -^ of that 

 quantity, or 87I. 13s. 4d. is the price at 3s. 4d. In like manner, 

 as 4d. is -iV of 3s* 4d. so -rV of 87I. 13s. 4d. or 81. 15s. 4d. is 

 the answer at 4d. And by reasoning ia this Way 4I. 7s. 8d. will 

 be shewn to'be the price at 2d. and' ids. 1 ifd. the price at f. — 

 Now as the sum of all these parts is equal to the whole price (3s. 

 lo^d.) so tlie sum of the answers, belonging to each price, will 

 be the answer at the full price required. And the same will be 

 true in any example v/lratevcr... 



