Errata – Foundations of GMAT Math, 4th Edition
Foundations of GMAT Math (Edition 4.1)
Edition 4.2 |
Edition 4.1 |
Edition 4.0 |
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Back Cover, Bottom Right CornerThe Foundations of GMAT Math Strategy Supplement (326 pages) provides a refresher of the basic math topics tested on the GMAT. Designed to be user-friendly for all students, this book provides easy-to-follow explanations of fundamental math concepts and step-by-step application of these concepts to example problems.
4.2
| Page | Loc | Description | Erroneous Text | Correction |
|---|---|---|---|---|
| 54 | Bot | The second sentence under the “Factoring Quadratic Equations” Heading factors the equation incorrectly. | It's not easy to look at x2 + 3x – 10 and see that it equals (x – 5)(x + 2). | It's not easy to look at x2 + 3x – 10 and see that it equals (x + 5)(x – 2). |
| 287 | Mid | In the second sentence of the explanation for #6, the 2 in the expression should be an exponent. | The radius of the circle is 10, so the area is ?(10)2, which equals 100?. | The radius of the circle is 10, so the area is ?(10)2, which equals 100?. |
| 300 | Mid | Drill Set 3, Drill 2, #5: Question refers to Triangle XYZ, but the picture depicts Triangle ABC. | ||
| 300 | Mid | Drill Set 3, Drill 2, #5: Question fails to mention that Triangle XYZ is a right triangle. | Triangle XYZ and Rectangle JKLM have equal areas… | Right Triangle XYZ and Rectangle JKLM have equal areas… |
| 134 | Mid | Drill Set 2, Drill 4, #1: The prime factorization of 18 given in the explanation is incorrect. 18 = 2 × 3 × 3, NOT 2 × 2 × 3 × 3. | 18 = 2 × 2 × 3 × 3, so 18 contains two 2's and two 3's. x contains two 2's, but… | 18 = 2 × 3 × 3, so 18 contains one 2 and two 3's. x contains one 2, but… |
| 315 | Bot | Explanation for Drill Set 3, Drill 2, #5: Question refers to Triangle XYZ, but the picture depicts Triangle ABC. |
4.1
| Page | Loc | Description | Erroneous Text | Correction |
|---|---|---|---|---|
| 67 | Mid | Set 2, Drill 4, #3. + should be – | x3 – 3x2 + 28x = 0 | x3 – 3x2 – 28x = 0 |
| 287 | Mid | In the second sentence of the explanation for #6, the 2 in the expression should be an exponent. | The radius of the circle is 10, so the area is ?(10)2, which equals 100?. | The radius of the circle is 10, so the area is ?(10)2, which equals 100?. |
| 134 | Mid | Drill Set 2, Drill 4, #1: The prime factorization of 18 given in the explanation is incorrect. 18 = 2 × 3 × 3, NOT 2 × 2 × 3 × 3. | 18 = 2 × 2 × 3 × 3, so 18 contains two 2's and two 3's. x contains two 2's, but… | 18 = 2 × 3 × 3, so 18 contains one 2 and two 3's. x contains one 2, but… |
| 54 | Bot | The second sentence under the “Factoring Quadratic Equations” Heading factors the equation incorrectly. | It's not easy to look at x2 + 3x – 10 and see that it equals (x – 5)(x + 2). | It's not easy to look at x2 + 3x – 10 and see that it equals (x + 5)(x – 2). |
| 300 | Mid | Drill Set 3, Drill 2, #5: Question refers to Triangle XYZ, but the picture depicts Triangle ABC. | ||
| 315 | Bot | Explanation for Drill Set 3, Drill 2, #5: Question refers to Triangle XYZ, but the picture depicts Triangle ABC. | ||
| 155 | Mid | Set 1, Drill 2, #9. The explanation incorrectly switches from z to x. | x(5 + (-3) – (-8)) = x10 | z(5 + (-3) – (-8)) = z10 |
| 256 | Top | There is a typo in the second sentence at the top of the page. | A right triangle is any triangle in which one of the angles is a right triangle. | A right triangle is any triangle in which one of the angles is a right angle. |
| 247 | Bot | Incorrect description of diameter in the text box. | d = diameter the distance around a circle | d = diameter the distance across a circle |
| 300 | Mid | Drill Set 3, Drill 2, #5: Question fails to mention that Triangle XYZ is a right triangle. | Triangle XYZ and Rectangle JKLM have equal areas… | Right Triangle XYZ and Rectangle JKLM have equal areas… |
| 67 | Mid | Set 2, Drill 4, #5. – 9x should be + 9x | -3x3 + 6x2 – 9x = 0 | -3x3 + 6x2 + 9x = 0 |
| 233 | Top | Set 1, Drill 1, #1. x < 4 should be x > 4. | x < 4 | x > 4 |
| 224 | Bot | In the first paragraph after the chart, change divide to multiply. | In each case, we begin with a true inequality statement: 5 < 7 and then divide by -1. | In each case, we begin with a true inequality statement: 5 < 7 and then multiply by -1. |
| 98 | Top | In the top line, the M should be a C. | Insert S – 14 for M in the second equation. | Insert S – 14 for C in the second equation. |
| 47 | Top | Drill 1, question 4 does not match the answer explanation provided on page 48. | 13 × 6 | 113 × 6 |
| 300 | Top | Set 3, Drill 2, #3. Side AD has a length of 8. | ||
| 34 | Mid | Set 2, Drill 4, #8. Answer explanation on page 38 is incorrect. See below. | ||
| 129 | Bot | Set 1, Drill 2, #3. Prime factorization is incorrect. The upper left circle should contain a 2, not a 5. | ||
| 36 | Mid | Set 1 Drill 4 is mislabeled.. | Set 1, Drill 5: | Set 1, Drill 4: |
| 314 | Bot | Set 3, Drill 2, #3. Side AD has a length of 8. | ||
| 240 | Mid | Set 5, Drill 2, #5. The inequality below the number line incorrectly switches <= to <. Also, the circles on the number line should be filled in. | -12 < x < 8/3 | -12 <= x <= 8/3 |
| 239 | Bot | Set 5, Drill 2, #2. The inequality below the number line is incorrect. | -14 < x < 6 | x < -14 or x > 6 |
| 239 | Bot | Set 5, Drill 2, #2. The number line is incorrect. The circles should be blank, not filled. | ||
| 232 | Mid | Set 5, Drill 2, #2. Answer explanation on pg 239 incorrect. See error below. | ||
| 239 | Bot | Set 5, Drill 2, #3. The explanation incorrectly switches from < to <=. |
|x3| <= 64
+ (x3) <= 64 or -(x3) <= 64 x3 <= 64 -x3 <= 64 x <= 4 x3 >= -64 x >= -4 |
|x3| < 64
+ (x3) < 64 or -(x3) < 64 x3 < 64 -x3 < 64 x < 4 x3 > -64 x > -4 |
| 123 | Top | Question #12 on page 111 has been amended. Refer to the listing on page 111. | ||
| 74 | Top | Set 2, Drill 4, #3. The first two lines of the explanation |
x3 – 3x2 + 28x = 0
x(x 2 – 3x + 28) = 0 -> x(x – 4)(x + 1) = 0 |
x3 – 3x2 – 28x = 0
x(x 2 – 3x – 28) = 0 -> x(x – 7)(x + 4) = 0 |
| 74 | Mid | Set 2, Drill 4, #5. The first two lines of the explanation |
-3x3 + 6x2 – 9x = 0
-3x(x 2 – 2x + 3) = 0 -> -3x(x – 3)(x + 1) = 0 |
-3x3 + 6x2 + 9x = 0
-3x(x 2 – 2x – 3) = 0 -> -3x(x – 3)(x + 1) = 0 |
| 130 | Bot | Set 1, Drill 4, #2. Ignore 3rd sentence. | 937,184 ends in 4, which means it's even. Therefore, it's divisible by 2. It's also divisible by 1 and. Prime numbers have only two factors… | 937,184 ends in 4, which means it's even. Therefore, it's divisible by 2. Prime numbers have only two factors… |
| 38 | Bot | Set 2, Drill 4, #8. Introduces a negative sign into the second line of the explanation. |
10(-3x + 4) = 2(10 – 5x)
-30x + 40 = 20 – 10x 40 = 20 + 20x 20 = 20x 1 = x |
10(3x + 4) = 2(10 – 5x)
30x + 40 = 20 – 10x 40x + 40 = 20 40x = -20 x = -1/2 |
| 131 | Mid | Set 1, Drill 6. 5 is prime and should be bolded. | ||
| 131 | Bot | Set 1, Drill 6. 27 is not prime. | Prime numbers: 2, 3, 5, 7, 17, 27, 29, 31 | Prime numbers: 2, 3, 5, 7, 17, 29, 31 |
| 87 | Mid | Set 2, Drill 5, #3. Eliminate last year. | If Joanna's team won 10 games last year, how many games did Eleanor's team win? | If Joanna's team won 10 games, how many games did Eleanor's team win? |
| 92 | Top | Set 2, Drill 2, #4. Change miles to kilometers. | Answer: Ben ran 11 miles. | Answer: Ben ran 11 kilometers. |
| 71 | Bot | Set 2, Drill 2, #4. The answers are incorrect. | Answer: c = -21 OR -3 | Answer: c = 21 OR 2 |
| 111 | Bot | CYS #12. Change 240 to 120. | 12. Find the prime factorization of 240. | 12. Find the prime factorization of 120. |
| 38 | Bot | Set 2, Drill 4, #8. Explanation needs to be replaced. |
10(3x + 4) = 2(10 – 5x)
30x + 40 = 20 – 10x 40x + 40 = 20 40x = -20 x = -1/2 |