Please explain no.3 fast....

3rd Transaction will be treated as ( Goods which costs Rs. 2400 were sold for Rs. 4000 which means there is a profit of Rs. 1600) . 
Effect in accounting equation will be...........    Goods decrease by 2400 ,     Cash increase by 4000 ,     capital increase by 1600..... 
 

Hope this will be enough to clear ur doubt.