Gujarat Board GSEB Textbook Solutions Class 8 Maths Chapter 1 Rational Numbers Ex 1.2 Textbook Questions and Answers.
Gujarat Board Textbook Solutions Class 8 Maths Chapter 1 Rational Numbers Ex 1.2
Question 1.
Represent these numbers on the number line.
- \frac { 7 }{ 4 }
- \frac { -5 }{ 6 }
Solution:
(i) To represent \frac { 7 }{ 4 } we make 7 markings each at a distance equal to \frac { 1 }{ 4 } on the right of 0.
The 7th point represents the rational number \frac { 7 }{ 4 } as shown in the figure.
The point A \frac { 7 }{ 4 }.
(ii) To represent (\frac { 7 }{ 4 }) on the nmber Line, we make 5 each at a distance equal to \frac { 1 }{ 6 } on the left of 0. We consider the 5th point as shwn in the figure
The point B represent (\frac { -5 }{ 6 })
Question 2.
Represent \frac { -2 }{ 11 }, \frac { -5 }{ 11 }, \frac { -9 }{ 11 }. on the number line.
Solution:
TO represent \frac { -2 }{ 11 }, \frac { -5 }{ 11 } and \frac { -9 }{ 11 } on a number line, we make 11 marking each being equal to distance \frac { 1 }{ 11 } on the left of 0.
- The point A represent \frac { -2 }{ 11 }
- The point B represent \frac { -5 }{ 11 }
- The point C represent \frac { -9 }{ 11 }
Question 3.
Write five rational numbers which are smaller than 2.
Solution:
There can be unlimited rational numbers smaller than 2. Five of them are:
0, -1, \frac { 1 }{ 2 }, \frac { 1 }{ 2 }, 1
Question 4.
Find ten rational numbers between \frac { -2 }{ 5 } and \frac { 1 }{ 2 }
Solution:
To convert \frac { -2 }{ 5 } and \frac { 1 }{ 2 } having the same denominators:
We have \frac { -2 }{ 5 } = \frac{-2 \times 4}{5 \times 4} = \frac { -8 }{ 20 } and \frac { 1 }{ 2 } = \frac{1 \times 10}{2 \times 10} = \frac { 10 }{ 20 }
∵ The rational numbers between \frac { 10 }{ 20 } and \frac { -8 }{ 20 } are \frac { 9 }{ 20 }, \frac { 8 }{ 20 }, \frac { 7 }{ 20 }, \frac { 6 }{ 20 }, …., \frac { -6 }{ 20 } , \frac { -7 }{ 20 }
We can take any 10 of them.
∵ ten rational nnumbers between \frac { -2 }{ 5 } and \frac { 1 }{ 2 } are:
(i) \frac { 9 }{ 20 }
(ii) \frac { 8 }{ 20 }
(iii) \frac { 7 }{ 20 }
(iv) \frac { 6 }{ 20 }
(v) \frac { 5 }{ 20 }
(vi) \frac { 4 }{ 20 }
(vii) \frac { 3 }{ 20 }
(viii) \frac { 2 }{ 20 }
(ix) \frac { 1 }{ 20 }
(x) 0
Question 5.
Find five rational numbers between:
- \frac { 2 }{ 3 } and \frac { 4 }{ 5 }
- \frac { -3 }{ 2 } and \frac { 5 }{ 3 }
- \frac { 1 }{ 4 } and \frac { 1 }{ 2 }
solution:
(i) Coverting \frac { 2 }{ 3 } and \frac { 4 }{ 5 } having same denominators such that difference between the numerators is more than 5.
We have \frac { 2 }{ 3 } = \frac{2 \times 20}{3 \times 20} = \frac { 40 }{ 60 } and \frac { 4 }{ 5 } = \frac{4 \times 12}{5 \times 12} = \frac { 48 }{ 60 }
Now, any five rational number between
\frac{40}{60}\left(=\frac{2}{3}\right) and \frac{48}{60}\left(=\frac{4}{5}\right) are: \frac { 41 }{ 60 }, \frac { 42 }{ 60 }, \frac { 43 }{ 60 } , \frac { 44 }{ 60 }, \frac { 45 }{ 60 }
(ii) Converting \frac { -3 }{ 2 } and \frac { 5 }{ 3 } with same denominators, we have
∴ Five rational numbers between
(iii) Converting \frac { 1 }{ 4 } and \frac { 1 }{ 2 } to rational numbers with the same denominators, we have
∴ Five rational numbers between \frac { 1 }{ 4 } and \frac { 1 }{ 2 } i.e., \frac { 8 }{ 32 } and \frac { 16 }{ 32 } are: \frac { 9 }{ 32 }, \frac { 10 }{ 32 }, \frac { 11 }{ 32 }, \frac { 12 }{ 32 }, \frac { 13 }{ 32 }
Question 6.
Write five rational numbers greater than – 2.
Solution:
Five rational numbers greater than – 2 are: \frac { -3 }{ 2 }, -1, \frac { -1 }{ 2 }, 0, \frac { 1 }{ 2 }
Note: There ten rationalnumbers greater than – 2
Question 7.
Find the rational numbers between \frac { 3 }{ 5 } and \frac { 3 }{ 4 }.
Solution:
Converting \frac { 3 }{ 5 } and \frac { 3 }{ 4 } such that they between \frac { 3 }{ 4 } and \frac { 3 }{ 4 } such that they have common denominators and their numerators have difference of more than 10, i.each