Two mixtures A and B contain milk and water in the ratios 2:5 and 5:4 respectively. How many gallons of A must be mixed with 90 gallons of B so that the resultant mixture contains 40% milk? Choose the correct choice from the following answers:	A) 144	B) 122.5	C) 105.1	D) 72	E) 134
Mixture A: 2:5 ratio of Milk:Water   Mixture B: 5:4 ratio of Milk:water   90 gallons mixture B with a ratio of 5:4 = 50 gallons of milk and 40 gallons of water 90/(5+4)= 
<gadget id="calculator">90/(5+4)</gadget>
<output>10</output>
10. 10*5= 50 and   10*4= 
<gadget id="calculator">  10*4</gadget>
<output>40</output>
40.   (50+(2/7x))/(90+x)= .40   50+(2/7x)=.4(90+x)   50+(2/7x)=(2/5x)+36   50+(10/35x)=(14/35x) +36   4/35x=14   4x=14*35   4x=490   x=122.5 gallons   ANSWER:122.5
<result>B</result>
Two mixtures A and B contain milk and water in the ratios 2:5 and 5:4 respectively. How many gallons of A must be mixed with 90 gallons of B so that the resultant mixture contains 40% milk?