A dishonest milkman wants to make a profit on the selling of milk. He would like to mix water (costing nothing) with milk costing Rs.42 per litre so as to make a profit of 20% on cost when he sells the resulting milk and water mixture for Rs.48 In what ratio should he mix the water and milk?
Options
A) 1:20 B) 1:10 C) 1:8 D) 1:4 E) 6:11
water = w (liter)   Milk = m (liter)   ==&gt; Cost = Price x Quantity = 0.42m   ==&gt; Revenue = Price x Quantity = 0.48(m + w)   ==&gt; Profit =0.48(m+w) - 0.42m = 0.2*(0.42m)[20% of cost]   ==&gt; 0.48m + 0.48w - 0.42m = 0.084m   ==&gt; 0.024m = 0.48w   ==&gt; m/w = 0.48/0.024= 
<gadget id="calculator">0.48/0.024</gadget>
<output>20</output>
20   --OR--   w/m= 1/20   1:20 is correct.
<result>A</result>
A dishonest milkman wants to make a profit on the selling of milk. He would like to mix water (costing nothing) with milk costing Rs.42 per litre so as to make a profit of 20% on cost when he sells the resulting milk and water mixture for Rs.48 In what ratio should he mix the water and milk?