14^ 



ARITHMETIC. 



afforded at 8d. per pound ; how much of each sort must 

 he take ? 



Ans. 721b. at 4d. 24 at 6d. 48 at pd. and 96 at ird. 

 3. How much gold of 15, of 17, of 18 and of 22 ca- 

 rats fine, must be mixed together to form a composition 

 of 40 ounces of 20 carats fine ? 



. Ans. 50Z. of 15, of 17 and of x8, and 25 of 22. 



RULE 3.* 



When one of the ingredients ' is linTited to a certain quantity .' 

 take the difference between each price and the mean rate 

 as before ; then, 



As the difference of that simple, whose quantity is given,^ 

 is to the re.st of the differences severally, so is the quanti- 

 ty given to the several quantities required. 



EXAMPLES. 



I. How 'much wine at cs. at 5s. 6d. and 63. the gallon 

 must be mixed v/ith 3 gallons at 4s. per gallon, so that the 

 mixture may ^e worth 5s. 4d. per gallon ? 



* In the very same manner questions may . be wrought, when 

 several of the ingredients are limited to certain quantities, by find- 

 inn first fbr one limit and thea for another. 

 t> 



The two last rules can want no demonstration, as they evident- 

 ly result from, the first, the reason of which has been already 

 explained. 



i 



