POSITION. 219 



EXAMPLES. 



I. A's age is double that of B, and B*s is triple that of" 

 C, and the sum of all their ages is 140 : what is each 

 person's age ? 



Suppose A's age to be 60, 

 Then will B's = V=30> 

 AndCs = V° = 10. 



100 sum. 

 As TOO : 60 : : 140 : :^^-?i^ =84= A's age. 

 Consequently \-* =42 = B*s. 

 And Y =i4 = Cs. 



140 Proof. 



2. A certain sum of money is to be divided between 4 

 |)ersons, in such a manner, that the first shall have y of it j 

 the second -^ ; the third y *, and the fourth the remainder, 

 which is 28I. : what is the sum ? Ans. 112I. 



3. A person, after spending — uxxd -^ of his money, had 

 60I. left : what had he at first ? Ans. 11 4J. 



4. What number is that, which being increased by ~, -^ 

 and -J of itself, the sum shall be 1 25 ? Ans. 60, 



5. A 



this case the reason of the rule is obvious ; it being then evident, 

 diat the results are proportional to the supposidons. 



Thus 



j — ,&c. : 5,&soon. 



n — m 



Note, i may be macie a constant supposition in all questions, 

 and in mi>st cases it is better tliao any other number. 



