In what ratio must water be added to 10 litres of milk at Rs.20 per litre so that cost of mixture is Rs.16 per litre?  Choose the correct answer
A) 3:2	B) 1:4	C) 2:3	D) 4:1	E) 4:3
C.P of 1 Lt of water =Rs.0   C.p Of 1 lt of Milk= Rs.20   So,   o(Cheaper) 20(Dearer)   16(Mixture)   4 : 16   (Dearer-Mixture) (Mixture-Cheaper)   so,   (Note: Just cross check)   4:16=1:4   ANSWER:1:4
<result>B</result>
In what ratio must water be added to 10 litres of milk at Rs.20 per litre so that cost of mixture is Rs.16 per litre?