13, because 78 postcards divided by 6 cards per board = 13 poster boards
The correct answer for the question that is being presented above is this one: "The reason for the difference can not be determined with the information that is given." Looking at the scatter plot of pages versus amazon price, it appears that the data might be clustered around two separate regression lines. The cause of the split in the data is that <span> the difference can not be determined with the information that is given</span>
The first thing to note is since one gallon= 60 miles then 1/2 gallon= 30 miles, now I know 1/2 is not an answer but it is easiest to decrease in moderate amounts. 1/2 gallon= 48 Km so we are close, and 1/2=0.5 so if we brought it down to 0.42 we would have 25.2 miles and 25.2 miles = 40.32. The question wants to know the approximate number and 40.32 is the closest we are going to get so the answer is 0.42