CAT Quantitative Aptitude Questions | CAT Algebra - Functions questions

The question is about Greatest Integer Function. Multiplication of a decimal and its Greatest Integer function is given and we need to find out the value of the decimal. Functions is a simple topic which involves a lot of basic ideas. Make sure that you a get of hold of them by solving these questions. A range of CAT questions can be asked based on this simple concept of Functions questions in the CAT Exam. Make sure you practice a lot of questions in CAT Functions Algebra to push your CAT preparation in the right direction. Functions as an idea is a fabulous idea if one can wrap their head around it the right way, and it has been one of the staple ideas tested by the CAT exam historically.

Question 17: Find the value of x for which x[x] = 15?

1. 3.5
2. 5
3. 6.1
4. None of these

Explanatory Answer

Method of solving this CAT Question from CAT Algebra - Functions: Multiplication of a decimal and its Greatest Integer function.

Using similar approach as previous question, [x] = 3
=> x = \\frac{15}{3}\\) => x = 5 which is not possible since 3 < x < 4

The question is "Find the value of x for which x[x] = 15?"

Hence the answer is "None of these"

Choice D is the correct answer.