IN A CERTAIN YEAR, MINNESOTA PRODUCED 21003 AND MICHIGANTHEREFORE,...

7. In a certain year, Minnesota produced 21003 and MichiganTherefore, the best answer is (A). However, the calculations areproduced 16 of all the iron ore produced in the Unitedunnecessary; classes 1 and 2 must have a mean greater than 85States. If all the other states combined produced 18 millionsince the mean of 89 and 81 is 85 and there are 20 more stu-tons that year, how many million tons did Minnesotadents in class 1 than in class 2. Since class 3 has a mean of 85,it must be true that the overall mean for the 3 classes is greaterproduce that year?than 85.(A) 27 (B) 36 (C) 54 (D) 72 (E) 162PROBLEM SOLVINGSince Minnesota produced 23 and Michigan produced 16 ^ofThe problem solving questions are standard multiple choiceall the iron ore produced in the United States, the two statesquestions with five answer choices. To answer a question,together produced 56 of the iron ore. Therefore, the 18 millionselect the best of the answer choices. Some problem solvingtons produced by the rest of the United States was 1questions are discrete while others occur in sets of two to five6 ^{of the}questions that share common information. For some of thetotal production. Thus the total United States production wasquestions, the solution requires only simple computations or(6)(18) = 108 million tons, and Minnesota producedmanipulations; for others, the solution requires multi-step prob-2lem solving.3(108) = 72 million tons. The best answer is (D).The following strategies may be helpful in answering problemsolving questions.