CREAMERY PROBLEMS. 287 



Problem: 670 lbs. starter were added to cream, 

 making a total of 3.200 lbs. of cream. What per cent 

 of starter was added? 



Rule: From the number of pounds of cream sub- 

 tract the number of pounds of starter, divide the 

 difference into the number of pounds of starter; 

 multiply the quotient by 100 and the result is the 

 per cent of starter. 



Solution : 3,200— 670^-2,530 ; ( 670h-2,530) X 100= 

 26.5%. Ans. 



Explanation: When any amount of starter has 

 been added to cream we first subtract the number 

 of pounds of starter from the total number of 

 pounds given. This gives the number of pounds of 

 cream before the startex was added. By dividing 

 the number of pounds of cream into the number of 

 pounds of starter and multiplying by 100 we get the 

 per cent of starter. 



What is the per cent of starter when: 



1. 1,600 lbs. of cream contain 300 lbs. of starter? 

 Ans. 23.07%. 



2. 4,000 lbs. of cream contain 600 lbs. of starter? 

 Ans. 17.6%o. 



3. 4,500 lbs. of cream contain 800 lbs. of starter? 

 Ans. 21.6%. 



4. 30,000 lbs. of cream contain 6,000 lbs. of 

 starter? Ans. 25%. 



5. 30,000 lbs. of cream contain 7,600 lbs. of 

 starter? Ans. 33.4%o. 



