How many litres of a 0.5 N solution of an oxidising agent are reduced by 2 litres of a 2.0 N solution of a reducing agent
I think this is the simplest calculation for Redox reaction in Chemistry.
What do you need to do is just balancing.
From your knowledge of chemistry you know that
V1N1=V2N2
Therefore substituting the values we get the answer
2*2=0.5*V2
V2=4/0.5
V2=8
Therefore the answer to your problem is 8 litres
V2=8