Question 1153035
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The distance between -5 and 60 in number line is 65 units.


From the other side, 12 arithmetic means (actually, 12 terms of an arithmetic progression)

divide the segment [-5,60] in 13 equal intervals, so each interval (the gap between the neighbor terms) is  65/13 = 5 units.


Each such gap is the common difference of the arithmetic prigression, so its common difference is 5.    <U>ANSWER</U>
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