Here is an interesting GMAT number property problem solving question. Concept tested : number of factors.Integer x has n factors; 3x has 3 factors; Which of the following values can n take? I. 1 II. 2 III. 3 A. I only B. II only C. I or II D. II or III E. I or III … [Read more...] about Number Properties Problem Solving : Factors

# factors

## Quadratic Equation PS – Sum of roots

This question is an interesting quadratic equation question that ties in concepts relating to factors in number properties.While solving questions of this kind exercise caution with what the question asks. You may do everything right and still end up with an incorrect answer.Questionx2 + bx + 72 = 0 has two distinct integer roots; how many values are possible for 'b'?A. 3B. … [Read more...] about Quadratic Equation PS – Sum of roots

## Number Properties – Factors

Here is a relatively easy number properties problem solving question.QuestionWhat is the largest 3 digit number to have an odd number of factors?A. 729B. 943C. 625D. 961E. 841Correct Answer : Choice D. 961Explanatory AnswerA perfect square has an odd number of factors.Of the numbers in the list, the largest 3 digit perfect square is 961 (312).Hence, Choice D is the correct … [Read more...] about Number Properties – Factors

## Number Properties – Product of factors

What is the product of all positive factors of 18? A. 324 B. 5832 C. 39 D. 1521 E. 3042 The correct answer is 5832. Choice B. Let us first focus on how to find the answer methodically and then understand why the method works. The How? Step 1: Find the number of factors for 18. Step 1a. Express 18 as a product of its prime factors. 18 = 2 * 3^2 Step 1b. Increment the … [Read more...] about Number Properties – Product of factors

## Number Properties – divisibility and remainders

When a positive integer A is divided by 5 and 7, the remainders obtained are 3 and 4, respectively. When the positive integer B is divided by 5 and 7, the remainders obtained are 3 and 4, respectively. Which of the following is a factor of (A - B)? (A) 12 (B) 24 (C) 35 (D) 16 (E) 30 Correct Answer : Choice C Explanatory Answer When A is divided by 5, the remainder is 3. So, … [Read more...] about Number Properties – divisibility and remainders