Joint and By product

a company manufactures three products A B and C they all are processed through a common process product A and B are main product and C is the by product the common cost of the process in month of may was 150000 following is the data related to every product in month of may
Output
A 1000
B 1500
C 500
SALES
A 800
B 1200
C 400
The NRV of by product is 2 per kg and is deducted from cost of main product selling price of product A is 100 and of B is 40 suppose that company uses sales value method for apportion joint cost What will be the profit loss of product B in may

5500 profit
5500 loss
3300 profit
3300 loss

Sir my answer is 7950 Which is not here I have deducted the NRV from main cost and then I have devided the revenue of product B by total revenue and then multiply it by joint cost which was (150000-800)
I did as follows
48000/128000*149500
And then subtract this from sales of B to find profit
Can you please tell what i did wrong
And the answer given is 3300 profit