27(i MODERN BUTTER MAKING. 



Problem: "What is the per cent of cream from 

 milk when a separator delivers 10 lbs. of cream to 

 every 40 lbs. of skim milk? 



Rule: Add the cream and skim milk separated at 

 one time, together; divide the cream pounds by the 

 sum, and multiply the quotient by 100. The result 

 will be the per cent of cream from milk. 



Solution: 10+40=50; 10-^50=^. % cream from 

 1 lb. milk. 



Or 10+40=50; 10Xl00-=-50=20% cream from 

 100 lbs. of milk. 



For every 50 lbs. of milk we get 10 lbs. of cream 

 and we get as many pounds of cream for every 

 pound of milk as 50 is contained in 10, which is .2, 

 and from every 100 lbs. of milk we get 100 X -2 or 

 20 lbs. or 20%. 



Problems for Practice. 



"What is the per cent of cream from milk when a 

 separator delivers: 



1. 10 lbs. of cream and 35 lbs. of skim milk? 



Ans. 22+%. 



2. 12 lbs. of cream and 60 lbs. of skim milk? 



Ans. 16+%. 



3. 15 lbs. of cream and 75 lbs. of skim milk? 



Ans. 17—%. 



4. 20 lbs. of cream and 88 lbs. of skim milk? 



Ans. 18+%. 



5. 24 lbs. of cream and 95 lbs. of skim milk? 



Ans. 20 + %. 

 59. To find the amount of cream of any desired 

 test which milk of any richness can yield. 



