725 - Math - Problem Solving

Question: A merchant mixes three varieties of rice costing Rs.20/kg, Rs.24/kg and Rs.30/kg and sells the mixture at a profit of 20% at Rs.30 / kg. How many kgs of the second variety will be in the mixture if 2 kgs of the third variety is there in the mixture?

1. 1 kg
2. 5 kgs
3. 3 kgs
4. 6 kgs