A sells an article to B making a profit of 1/5 th his outlay. B sells it to C, gaining 20%. If C sells it for Rs 600 and incurs a loss of 1/6 th his outlay, the cost price of A is: 1. Rs 600
2. Rs 500
3. Rs 720
4. Rs 800
2. Rs 500
3. Rs 720
4. Rs 800