Graduate Management Admission Test (GMAT) Practice Test

What is the result when testing a 3-digit number for divisibility by 11?

1. The units and hundreds should equal the tens

2. The number must be even

3. The sum of all digits should equal a multiple of 11

4. Units should equal hundreds and tens

The correct answer is: The units and hundreds should equal the tens

When testing a 3-digit number for divisibility by 11, the correct approach involves checking the relationship between the digits in specific positions. The rule for divisibility by 11 states that a number is divisible by 11 if the difference between the sum of its digits in the odd positions and the sum of its digits in the even positions results in a number that is either 0 or a multiple of 11. For a 3-digit number structured as ABC, where A is the hundreds digit, B is the tens digit, and C is the units digit, we can apply the rule as follows: The digits in odd positions are A and C, while the digit in the even position is B. So, to determine if the number is divisible by 11, you would calculate (A + C) - B. The correct answer emphasizes that the units and hundreds digits (A and C) should be compared to the tens digit (B) to establish this relationship. If A plus C equals B, or the difference between these sums equals 0 or a multiple of 11, then the number is divisible by 11. This analysis confirms that the units and hundreds digits must relate to the tens digit for the number to meet the