Answer:
No. of shares of stock a = 4000
Gain from share a. = Rs . 3 / share.
Total gain from share a = Rs. ( 4000 × 3 )
= Rs . 12,000.
Similarly ,
No. of shares of stock b = 5000
Loses from share b. = Rs. 2 / share.
Total loss from share b. = Rs. ( 5000 × 2 )
= Rs. 10,000.
Net gain -:
= Rs. ( 12,000 - 10,000 )
= Rs. 2000