How many litres of pure acid are there in 10 litres of a 25% solution
Pick one:  A) 1.5  B) 1.6  C) 2.5  D) 1.8  E) 1.9
Explanation:
Question of this type looks a bit typical, but it is too simple, as below... It will be 10 * 25/100= 
<gadget id="calculator">10 * 25/100</gadget>
<output>5/2 = around 2.5</output>
2.5 Answer: Option 2.5
<result>C</result>
How many litres of pure acid are there in 10 litres of a 25% solution