problem in pgbp sec 40(b)

net profit of firm =500,000 after debited credited given below amounts...
1 debited 100,000 salary paid to employees by crossed cheque
2 Dr 400,000 cost of car purchased and put to use on 31.3.2017
3 Dr 300,000 interest paid to Mr x @ 15% p.a
4 Dr 450000 interest paid to Mr y @ 15% p.a
5 Dr salary 100,000 paid to Mr x
6 Dr salary 500,000 paid to Mr y
7 Dr advance tax rs 800,000
8 credited long term capital gain 600,000
the firm has b/f business loss 300,000
the firm had donated rs 40000 to charitable institution notified u/s 80G
firm complied all conditions given in section 184/40(b) and payment of salary and interest is allowed as per the instrument.
compute tax liability of partners and also firm a.y 2017 18 ...........
Please solve this question em not getting correct ans....