Official Guide Explanations:
Questions by Content Area

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.

Algebra > Absolute Value
PS
152, 156
DS
103, 120

Algebra > Equations
PS
3, 28, 42, 54, 99, 106, 111, 115, 116, 118, 124, 171, 172
DS
5, 37, 61, 74, 83, 94, 100, 105, 108, 109, 118, 119, 124

Algebra > Exponents
PS
4, 55, 74, 96, 147, 166, 170
DS
18, 25, 28, 37, 54, 76, 81, 100, 121

Algebra > Functions
PS
67, 131, 149, 158
DS
107, 111

Algebra > Inequalities
PS
92, 117, 122, 123, 134, 156
DS
32, 34, 40, 41, 42, 51, 52, 56, 68, 69, 82, 89, 96, 102, 120

Algebra > Linear Equations-One Unknown
PS
1, 2, 5, 25, 32, 40, 53, 57, 61, 84, 91, 96, 107, 113, 114, 121, 125, 140, 161, 164, 170
DS
15, 26, 27

Algebra > Linear Equations-Two Unknowns
PS
13, 24, 30, 41, 62, 77, 92, 105, 115, 152, 174
DS
1, 4, 6, 7, 9, 13, 14, 23, 25, 30, 33, 35, 44, 46, 50, 53, 57, 60, 61, 73, 75, 80, 84, 95, 97, 108

Algebra > Simplifying Algebraic Expressions
PS
40, 42, 74, 76, 99, 104, 105, 107, 111, 121, 128, 133, 134, 156
DS
48

Algebra > Solving Equations by Factoring
PS
103, 108, 133
DS
106

Algebra > Solving Quadratic Equations
PS
20, 57, 72, 103
DS
37, 46, 62, 73

Algebra > Symbolism
PS
65, 113, 144, 174
DS
96, 102

Arithmetic > Counting Methods
PS
132, 151
DS
None

Arithmetic > Decimals
PS
6, 27, 29, 45, 47, 58, 65, 84, 86, 93, 97
DS
None

Arithmetic > Descriptive Statistics
PS
32, 63, 70, 81, 84, 104, 116, 129, 137, 148, 154, 161
DS
1, 14, 34, 41, 66, 74, 75, 101, 103, 112, 118

Arithmetic > Discrete Probability
PS
79, 160
DS
122

Arithmetic > Fractions
PS
2, 5, 8, 14, 16, 27, 29, 35, 39, 45, 46, 47, 48, 50, 53, 58, 59, 60, 64, 87, 88, 93, 97, 118, 129, 165, 167, 168, 176
DS
2, 15, 29, 48, 55, 57, 68, 94, 106, 107, 119, 120, 124

Arithmetic > Percents
PS
9, 10, 12, 15, 33, 34, 38, 43, 49, 52, 66, 73, 89, 95, 100, 101, 114, 120, 127, 138, 143, 154, 155, 159
DS
5, 17, 33, 36, 42, 50, 53, 63, 67, 75, 116

Arithmetic > Powers and Roots of Numbers
PS
4, 8, 20, 22, 36, 47, 50, 86, 88, 90, 97, 108, 121, 147, 163, 166, 169, 170
DS
3, 16, 18, 24, 28, 31, 51, 54, 64, 76, 78, 79, 81, 104, 109, 110, 113, 121

Arithmetic > Properties of Integers
PS
11, 31, 55, 68, 70, 78, 79, 83, 98, 109, 112, 122, 125, 144, 149, 163, 164, 169, 172, 174
DS
3, 16, 20, 21, 31, 35, 39, 44, 45, 49, 64, 66, 70, 78, 82, 86, 87, 90, 92, 104, 110, 112, 115

Arithmetic > Ratio and Proportion
PS
6, 37, 39, 82, 110, 124, 126, 130, 139, 155, 168, 173, 175
DS
6, 9, 17, 42, 57, 67, 71, 77, 88

Arithmetic > Real Numbers
PS
17, 106, 117, 123, 166
DS
24, 30, 68, 70, 79, 96, 98, 102

Arithmetic > Sets
PS
18, 26, 64, 69, 146
DS
8, 10, 63, 85, 116

Geometry > Circles
PS
33, 141, 145, 153, 162
DS
22, 58, 59, 88, 95, 99

Geometry > Coordinate Geometry
PS
21, 83, 85, 102, 123
DS
22

Geometry > Intersectings Lines and Angles
PS
30
DS
123

Geometry > Lines
PS
7
DS
11, 58, 72

Geometry > Polygons (Convex)
PS
150
DS
None

Geometry > Quadrilaterals
PS
15, 24, 76, 135, 141, 175
DS
4, 43, 60, 114

Geometry > Rectangular Solids and Cylinders
PS
139
DS
None

Geometry > Triangles
PS
44, 71, 85, 145, 153, 157, 162
DS
19, 43, 65, 88, 91, 114, 123

Word Problems > Data Interpretation
PS
19, 56, 148
DS
93

Word Problems > Discount
PS
9, 34, 38, 66, 73, 89, 100, 101
DS
None

Word Problems > Geometry Problems
PS
15, 24, 33, 175
DS
4, 60, 99

Word Problems > Measurement Problems
PS
22, 23, 77
DS
None

Word Problems > Mixture Problems
PS
54, 95, 137, 143, 154, 155
DS
None

Word Problems > Other
PS
1, 3, 10, 12, 13, 61, 69, 75, 80, 81, 91, 112, 114, 118, 120, 127, 159, 160, 165, 167
DS
5, 12, 13, 14, 21, 26, 27, 29, 36, 53, 77, 82, 84, 97, 117, 122

Word Problems > Profit
PS
25, 171
DS
None

Word Problems > Rate Problems
PS
23, 28, 35, 37, 46, 49, 51, 52, 59, 82, 90, 94, 110, 119, 124, 126, 136, 142, 168
DS
38, 47, 55, 59, 71, 117

Word Problems > Sets
PS
18, 26, 64, 69, 132, 146
DS
8, 10, 63, 85, 116

Word Problems > Work Problems
PS
16, 87, 130, 140, 173
DS
38, 47

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