請問GWD3----math no.37怎解?

[pipson]

為何算不出標準答案???

In 1995 a certain store had 1,800 tools in stock that had been purchased for $30 each. If 1,000 of these tools were sold in 1995 for $40 each and the remaining 800 were sold in 1996 for $50 each, how many greater was the gross profit on the tools sold in 1996 than the gross profit on those sold in 1995?
(A) $0
(B) $6,000
(C) $8,000
(D) $32,000
(E) $40,000

答案是(B), 請問是怎算出來的?????

[micki]

1996 profit = 800*50 - 800*30 = 40,000-24,000 = 16,000

1995 profit = 1,000*40 - 1,000*30 = 40,000-30,000 = 10,000

16,000 - 10,000 = 6,000

[pipson]

1996 profit = 800*50 - 800*30 = 40,000-24,000 = 16,000

1995 profit = 1,000*40 - 1,000*30 = 40,000-30,000 = 10,000

16,000 - 10,000 = 6,000

OH~~~~i see
million thanks!