Table of Contents
Overview
There are 4 questions in Class 9 Maths Exercise 1.1 The questions and their solutions with examples are explained in easy language.
Question/Answers
| S.No. | Question & Answer |
| Q. 1. | Is zero a rational number? Can you write it in the form, where p and q are integers and q is not equal to 0? |
| Ans: | Consider the definition of a rational number – A rational number is one that can be written in the form of p/q and where p and q are integers and q is not equal to 0. Zero can be written as 0/1, 0/2, 0/3, etc. So, we arrive at the conclusion that 0 can be written in the form of p and q where q is any integer. We can also take q as a negative integer. Therefore, zero is a rational number. |
| Q. 2. | Find six rational numbers between 3 and 4. |
| Ans: | We know that there are infinite numbers between two rational numbers. therefore, six rational numbers between 3 and 4 can be: Let a=3 and b=4 so (a+b)/2=(3+4)/2=7/2 Let a=3 and b=7/2 so (3+7/2)/2= 13/4 Let a=4 and b=7/2 so (4+7/2)/2= 15/4 Let a=7/2 and b=13/4 so (7/2+13/4)/2= 27/8 Let a=13/4 and b=15/4 so (13/4+15/4)/2= 28/8 Let a=7/2 and b=15/4 so (7/2+15/4)/2= 29/8 7/2, 13/4, 15/4, 27/8, 28/8, 29/8 are the six rational numbers between 3 and 4. Easy Alternate Method: We can write 3=21/7 and 4=28/7 so six rational numbers between 3 and 4 are: 22/7, 23/7, 24/7, 25/7, 26/7, 27/7. The answer may vary because of infinite numbers present between two numbers. |
| Q3. | Find five rational numbers between 3/5 and 4/5. |
| Ans. | Firstly, we make the numerator and denominator the same by multiplying with 6, a number greater than 5. We get, 3×6/5×6= 18/30 and 4×6/5×6= 24/30 so five rational numbers between 3/5 and 4/5 are: 19/30, 20/30, 21/30, 22/30, 23/30. |
| Q4. | State whether the following statements are true or false. Give Reasons for your answers. (i) Every Natural Number is a whole number. (ii) Every Integer is a whole number. (iii) Every Rational Number is a Whole Number. |
| Ans. | (i) True, because the collection of all natural numbers and 0 are called whole numbers. (ii) False, because negative integers are not Whole Numbers. (iii) False, because Rational Numbers are in the form of p/q where q ≠ 0, and if q is not completely divided by p then it is not a Whole Number. |
Video Explanation
Maths Concepts
To understand maths concepts of Rational numbers, Integers, etc used in NCERT Class 9 Maths Exercise 1.1, please also check the following articles: