Solution:Concept- We needed to form an equation in terms of 'm' for how many miles Darin must drive. Let us assemble the hints given in the question that m miles given by Sam and twice that has been driven by Kara, and as for Darin it is 20 miles less.
Here, Number of miles driven by Sam Since Kara drove twice as many miles as Sam,
Number of miles drove by Since Darin drove 20 fewer miles than Kara,
Number of miles drove by Darin Number of miles drove by Kara Therefore, Darin drove miles.
Hence, the correct answer is option 2) .