Here is a question on selecting one or more objects from a set of object, all of which are not distinct.QuestionThere are 4 identical pens and 7 identical books. In how many ways can a person select at least one object from this set?a. 12b. (24 - )(27 -1)c. 11d. 211 - 1e. 39Correct Answer : Choice … [Read more...]

## Counting Methods : GMAT Problem Solving

QuestionHow many odd 4 digit positive integers that are multiples of 5 can be formed without using the digit 3?a. 900b. 729c. 3240d. 648e. 1296Correct Answer : Choice D. 648Explanatory AnswerFollowing conditions are stated1. The number is a 4 - digit number.2. It is an odd number.3. It is a multiple … [Read more...]

## Permuations and digits

1. How many six digit positive integers comprising only the digits 1 and 2 exist such that the number is divisible by 3?For a number to be divisible by 3, the sum of the digits must be divisible by 3.Case 1: 111111: This can rearrange in only one way.Case 2: 222222: This can rearrange in only one … [Read more...]