Official Guide Explanations:
Questions by Difficulty Level

Background

This directory links you to hundreds of free explanations I've created to the quantitative questions in The Official Guide for GMAT Quantitative Review (2nd ed.). There are lists of explanations sorted by question number, difficulty level, and content area. I've also created explanations for the quant problems in the 12th edition of the Official Guide.

These are the same explanations that are featured in my "Guides to the Official Guide" PDF booklets. However, because of the limitations of HTML and cross-browser compatibility, some mathematical concepts, such as fractions and roots, do not display as clearly online.

Click here for an example of the PDF booklets. Click here to purchase a PDF copy.

3 (Very Easy)
Problem Solving
2, 3, 6, 8, 10, 12, 17, 19, 39
Data Sufficiency
11, 12, 36, 65

4 (Moderately Easy)
Problem Solving
1, 4, 5, 7, 9, 11, 13, 14, 15, 20, 27, 28, 29, 32, 36, 37, 40, 41, 42, 43, 45, 46, 47, 48, 49, 50, 51, 52, 53, 55, 58, 59, 61, 63, 73, 74, 75, 88, 89, 93, 94, 95, 121
Data Sufficiency
2, 4, 5, 7, 8, 9, 10, 14, 15, 17, 18, 19, 20, 23, 24, 25, 26, 27, 29, 32, 33, 40, 57, 66, 73, 84, 93, 97, 101

5 (Moderate)
Problem Solving
16, 18, 21, 22, 23, 24, 25, 26, 30, 31, 33, 34, 38, 44, 54, 57, 60, 62, 65, 66, 69, 70, 71, 72, 77, 80, 82, 84, 86, 87, 90, 92, 97, 98, 99, 100, 101, 102, 104, 106, 107, 108, 109, 114, 115, 117, 118, 122, 123, 125, 126, 127, 128, 129, 132, 133, 135, 136, 137, 138, 139, 143, 148, 158, 159, 163, 164, 165, 167, 170, 176
Data Sufficiency
1, 3, 6, 13, 22, 28, 30, 34, 35, 37, 38, 39, 41, 43, 44, 45, 47, 48, 50, 53, 54, 56, 58, 60, 61, 62, 64, 67, 68, 69, 71, 72, 74, 75, 76, 77, 78, 79, 80, 81, 82, 85, 86, 88, 90, 92, 94, 95, 98, 99, 100, 103, 105, 108, 109, 110, 111, 113, 115, 116, 117, 118, 119

6 (Moderately Difficult)
Problem Solving
35, 56, 64, 67, 68, 76, 78, 79, 81, 83, 85, 91, 96, 103, 105, 111, 112, 113, 116, 119, 120, 124, 130, 131, 134, 140, 141, 142, 144, 146, 147, 150, 151, 152, 153, 154, 155, 156, 157, 161, 162, 166, 168, 171, 172, 175
Data Sufficiency
16, 21, 42, 46, 49, 51, 52, 55, 59, 63, 70, 83, 87, 89, 91, 96, 102, 104, 106, 112, 114, 120, 121, 122, 123, 124

7 (Very Difficult)
Problem Solving
110, 145, 149, 160, 169, 173, 174
Data Sufficiency
31, 107

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