Running at the same constant rate,6 identical machines can produce a total of 270 bottles per minute.At this rate,how many bottles could 8 such machines produce in 4 minutes ?	Choose the correct choice
A) 648
B) 1800
C) 2700
D) 1440
E) none of these

Rationale: "solution let the required number of bottles be x . more machines , more bottles ( direct proportion ) more minutes , more bottles ( direct proportion ) â ˆ ´ 6 ã — 1 ã — x = 8 ã — 4 ã — 270 â ‡ ” x = 8 x 4 x 270 / 6 = 1440 . answer d"
Answer: D