Tax from sale of mutual funds

Hi Friends,

I have a query on tax treatment on part sale of mutual funds units which were invested through SIP(Monthly investment) mode.

Suppose I invest Rs. 1000 each month a MF.first month i receive 100 units @ rs 10 per unit ,second month 90 units @ 11.11 per unit and so forth. At the end of 12th month ,i sale 150 units @ 14 per unit .Now my question is how do to determine whether it will be short term or long tem gains and what would be cost price(to follow FIFO or average price).

Thanks ,

Pooja Agarwal