SELLING CREAM AND ICE CREAM 



265 



Draw a rectangle with two diagonals, as shown below. 

 At the left hand corners place the tests of the milks or 

 creams to be mixed. In the center place the richness 

 desired. At the right hand corners place the differences 

 between the two numbers in line with these corners. The 

 number at the upper right hand corner represents the 

 number of pounds of milk or cream to use with the rich- 

 ness indicated in the upper left hand corner. Likewise 

 the number -at the lower right hand corner represents the 

 number of pounds of milk or cream to use with the 

 richness indicated in the lower left hand corner. 



Example: How many pounds each of 30% cream and 

 3.5% milk required to make 25% cream? 



35% 



Las, 



21.5, the difference between 3.5 and 25, is the number 

 of pounds of 30% cream needed ; and 5, the difference 

 between 25 and 30, is the number of pounds of 3.5% 

 milk needed. 



From the ratio of milk and cream thus found, any 

 definite quantity is easily made up. If, for example, 300 

 pounds of 25% cream is desired, the number of pounds 

 each of 30% cream and 3.5% milk is determined as fol- 

 lows: 



