An interesting GMAT problem solving practice question that combines two topics - counting methods and elementary number properties related to divisibility of numbers by 4. Question How many five digit positive integers comprising only the digits 1, 2, 3, and 4, each appearing at least once, exist such that the number is divisible by 4?120 24 72 60 … [Read more...] about Permutation and Divisiblity

# GMAT Permutation Combination

## Permutation Combination : Selecting from non distinct object

An interesting GMAT problem solving practice question in permutation combination. The concept covered in this question is selecting one or more objects from a set of object, all of which are not distinct. The objects not being distinct is what makes this question an interesting one. This is another question that you can use as a template to solve questions that comprise … [Read more...] about Permutation Combination : Selecting from non distinct object

## Counting Methods : GMAT Problem Solving

This GMAT permutation combination practice question is a classic counting methods question focusing on numbers and number properties. You can use the explanation given in this question as a template to solve questions of this kind. After cracking the question, create your own variants of this question and try solving them to master this idea. Question How many odd 4 digit … [Read more...] about Counting Methods : GMAT Problem Solving

## Permutation of Digits & Divisibility

This is an interesting counting methods question that combines a very basic rule of test of divisibility of number by 3. Question How many six digit positive integers comprising only the digits 1 and 2 can be formed such that the number is divisible by 3?3 20 22 38 360 Correct Answer Choice C. 22 such numbers can be formed. Explanatory … [Read more...] about Permutation of Digits & Divisibility

## Permutation Combination and Probability – Sampling with / without ordering

The next parameter on which sampling can be classified is Sampling based on whether Ordering (Arrangement) of the elements selected is considered or not. In this case too, as in the case of sampling with or without replacement let us look at two examples that will help us learn the concept better.Example 1. In how many ways can a group of students elect a President and a Vice … [Read more...] about Permutation Combination and Probability – Sampling with / without ordering