Turner corporation acquired two inventory items at a lump sum cost of $100,000. The acquisition included 3,000 units of product LF, and 7000 units of product 1B. LF normally sells for $30 per unit and 1B for $10 per unit. If Turner sells 1000 units of LF what amount of gross profit should it recognize?

a) $3750

b) $11250

c) $20000

d) 23,750

I know the answer is B but i do not know why it is B. Can someone please explain?