Since you are looking for an amount that would make the Mammoth Printing Company's price greater than Colossal Printing's price, you have an inequality.Plugging In on an inequality question means selecting a value for x that answers the question, and then comparing it to the inequalities in the answer choices. Remember, you may have to try more than one number with inequality questions, since the number you try first may satisfy the inequality in more than one answer choice!Start out by trying a small number, like x=2. Since x is the number of colors of ink used, Mammoth Printing Company would charge $ 28 to print the poster, plus $ 7 for each of the 2 colors, for a total of $42. Colossal Printing would charge $ 34 to print the poster, plus $ 5.50 for each of the 2 colors, or $ 45 total.That means that when x=2, Mammoth Printing Company would charge less than Colossal Printing, and 2 is not a number that works as a solution to this problem.Try a bigger number, such as x=5. If the poster had 5 colors, Mammoth Printing Company would charge $ 28 to print the poster, plus $ 7 for each of the 5 colors, for a total of $ 63. Colossal Printing would charge $34 to print the poster, plus $ 5.50 for each of the 5 colors, or $61.50 total. That means that when x=5, the price Mammoth charges would be more than Colossal's price, so this is a possible value for x.Once you have a value for x that satisfies the question, it's time to move to the answer choices. You should eliminate (A) and (B), because x=5 does not satisfy either of those inequalities. Choices (C) and (D) are satisfied when x=5, so they are still possible.Next, you need to find a number that will satisfy the inequality in one of the remaining answer choices but not the other, so you can determine whether (C) or (D) is your final answer. Looking at the answer choices, you can see that we will have to think about plugging in a number that will eliminate one answer choice but not the other. Try out x = 4, because it satisfies (C) but not (D). Mammoth Printing Company would charge $56 for a 4-color poster. $28 + $7(4) = $56 Colossal Printing would also charge $56 for a 4-color poster. $34 + $5.50(4) = $56 Since Mammoth would not charge more to print the poster than Colossal, you can eliminate (C) and choose (D).