running at the same constant rate, 6 identical machines can produce a total of 270 pens per minute. at this rate, how many pens could 10 such machines produce in 4 minutes?  Choose the correct choice from the following choices.
A) 1500 B) 1545.6 C) 1640.33 D) 1800 E) none of these
<gadget id="calculator">270 / 6</gadget>
<output>45</output>

<gadget id="calculator">45 * 4</gadget>
<output>180</output>

<gadget id="calculator">180 * 10</gadget>
<output>1_800</output>

<result>D</result>
running at the same constant rate, 6 identical machines can produce a total of 270 pens per minute. at this rate, how many pens could 10 such machines produce in 4 minutes?
multiply(multiply(divide(270, 6), 4), 10)
"explanation : let the required number of bottles be x . more machines , more bottles ( direct proportion ) more minutes , more bottles ( direct proportion ) machines 6 : 10 | | : : 270 : x time 1 : 4 | = > 6 * 1 * x = 10 * 4 * 270 = > x = ( 10 * 4 * 270 ) / 6 = > x = 1800 answer : d"