Class Nine Chapter 1 NCERT Solutions
CLASS 9 CHAPTER 1: NUMBER SYSTEMS
Exercise 1.1 Part 1
1. Is zero a rational number? Can you write it in the form p/q
where p and q are integers and q ≠ 0?
Sol. Yes, zero is a rational number. It can be written as
where p and q are
integers
and q ≠ 0.
- Find
six rational numbers between 3 and 4.
Sol. To find six rational numbers between 3 and 4, the denominator should be made equal to 6 + 1 = 7
Class Nine Chapter 1 NCERT Solutions
Six rational numbers between 3 and 4 can be found by varying the numerators between 21 and 28. Or, the numbers are
- Find five rational numbers between 3/5 and 4/5
Sol. To find five rational numbers between 3/5 and 4/5
we may add the given numbers and divide by 2, and repeat the process.
Many answers are possible to this question. There are of course infinitely many rational numbers between 3/5 and 4/5.
4. 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.
Sol. (i) True. Since the collection of whole numbers contains all the natural numbers.
(ii) False. Negative integers are not whole numbers.
