put options with strike k$1=10,$ k$2=20,$ k$3=40.$ with p$($k$1)=$ $$3,$ p$($k$2)=$ $$5,$ p$($k$3)=$ $$6.$ Is there an arbitrage opportunity? if yes, how can you make a risk$-$free profit? can you explain the math behind it$?$