Class 9 - Mathematics
Number System - Exercise 1.1
Top Block 1
Exercise 1.1
Question : 1:Is zero a rational number? Can you write it in the form p/q where p and q are integers and q ≠ 0?
Answer :
Yes, zero is a rational number. It can be written in the form p/q.
For example: 0/1, 0/2, 0/5 etc. are rational numbers where p and q are integers and q ≠ 0.
Question : 2:Find six rational numbers between 3 and 4.
Answer :
To get six rational numbers between 3 and 4, the denominator must be 6 + 1 = 7
Here, 3 = (3 * 7)/7 = 21/7 and 4 = (4 * 7)/7 = 28/7
So, the six rational can be obtained by changing numerator from 22 to 27.
Therefore, six rational numbers are: 22/7, 23/7, 24/7, 25/7, 26/7, 27/7
Question : 3:Find five rational numbers between 3/5 and 4/5.
Answer :
By converting these numbers into decimal, we have
3/5 = 0.6 and 4/5 = 0.8
Hence, the five rational numbers between 3/5 and 4/5 are: 0.61, 0.62, 0.63, 0.64, 0.65.
Mddle block 1
Question : 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.
Answer :
(i) True statement
The collection of all natural numbers and 0 is called whole numbers.
(ii) False statement
Integers such as –1, –2 are non-whole numbers.
(iii) False statement
Rational numbers like 1/2, 1/5, 2/7, etc. are not a whole number.