How to Compute limit of donation under Section 80 G?

RAHUL SINGH (Student CA Final ) (69 Points)

19 March 2018  
Upto FY 2016-17 donation in cash can be given upto a limit of Rs. 10,000 u/s 80 G. So how, limit is computed, is it payment wise or donee wise.
Please give the answer in following case:
Donation given in cash of Rs. 9000 4 times to a trust aggregating to Rs. 36000 in a FY. How much donation is eligible u/s 80 G?
Please answer giving relevant legal provisions supporting your answers.