Consider a batch distillation process for an equimolar mixture of benzene and toluene at atmospheric pressure. The mole fraction of benzene in the distillate collected after $10$ minutes is $0.6$. The process is further continued for additional $10$ minutes. The mole fraction of benzene in the total distillate collected after $20$ minutes of operation is

1. less than $0.6$
2. exactly equal to $0.6$
3. exactly equal to $0.7$
4. greater than $0.7$