#### Rational Numbers Model Question Paper

8th Standard EM

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Maths

Time : 01:30:00 Hrs
Total Marks : 50
4 x 1 = 4
1. The number which is subtracted from $\frac { -6 }{ 11 }$ to get $\frac { 8 }{ 9 }$

(a)

$\frac { 34 }{ 99 }$

(b)

$\frac { -142 }{ 99 }$

(c)

$\frac { 142 }{ 99 }$

(d)

$\frac { -34 }{ 99 }$

2. The sum of the digits of the denominator in the simplest form of $\frac { 112 }{ 528 }$

(a)

4

(b)

5

(c)

6

(d)

7

3. $\frac { 3 }{ 4 } \div \left( \frac { 5 }{ 8 } +\frac { 1 }{ 2 } \right)$

(a)

$\frac { 13 }{ 10 }$

(b)

$\frac { 2 }{ 3 }$

(c)

$\frac { 3 }{ 2 }$

(d)

$\frac { 5 }{ 8 }$

4. $\frac { 1 }{ 2 } -\left( \frac { 3 }{ 4 } -\frac { 5 }{ 6 } \right) \neq \left( \frac { 1 }{ 2 } -\frac { 3 }{ 4 } \right) -\frac { 5 }{ 6 }$ illustrates that subtraction does not satisfy the ________ property for rational numbers.

(a)

commutative

(b)

closure

(c)

distributive

(d)

associative

5. 5 x 1 = 5
6. $\frac { -19 }{ 5 }$ lies between the integers ______________ and ________________

()

-4 and -3

7. The value of $\frac { -5 }{ 12 } +\frac { 7 }{ 15 }$ = ________________

()

$\frac { 1 }{ 20 }$

8. If -3 x $\frac { -6 }{ 11 }$ = $\frac { -6 }{ 11 } \times x$ is _______________

()

-3

9. If $x\times \frac { -55 }{ 63 } =\frac { -55 }{ 63 } \times x=1$ then x is called the _______________ of $\frac { 55 }{ 63 }$

()

Multiplicative Inverse

10. The multiplicative inverse of -1 is ________.

()

-1

11. 5 x 1 = 5
12. 0 is the smallest rational number

(a) True
(b) False
13. The rational number that does not have a reciprocal is 0.

(a) True
(b) False
14. The rational numbers that are equal to their additive inverses are 0 and –1.

(a) True
(b) False
15. The additive inverse of $\frac { -11 }{ -17 }$ is $\frac { 11 }{ 17 }$

(a) True
(b) False
16. The multiplicative inverse exists for all rational numbers

(a) True
(b) False
17. 10 x 2 = 20
18. List five rational numbers between
–2 and 0

19. Draw the number line and represent the following rational numbers on it.
$\frac { -8 }{ 3 }$

20. Using average, write 3 rational numbers between $\frac { 14 }{ 5 }$ and $\frac { 16 }{ 3 }$

21. Evaluate: $\frac { 9 }{ 2 } \times \frac { -11 }{ 3 }$

22. Divide: -2 by $\frac { -6 }{ 15 }$

23. Arrange the following rational numbers in ascending and descending order
$\frac { -17 }{ 10 } ,\frac { -7 }{ 5 } ,0,\frac { -2 }{ 4 } ,\frac { -19 }{ 20 }$

24. In a constituency, $\frac { 19 }{ 25 }$ of the voters had voted for candidate A whereas $\frac { 7 }{ 50 }$ had voted for candidate B. Find the rational number of the voters who had voted for others.

25. A piece of wire is $\frac { 4 }{ 5 }$ m long.  If it is cut into 8 pieces of equal length, how long will each piece be?

26. Show that $\left( \frac { \frac { 7 }{ 9 } -5 }{ \frac { 4 }{ 3 } } \right) \div \frac { 3 }{ 2 } +\frac { 4 }{ 9 } -\frac { 1 }{ 3 } =-2$

27. Explain why the statements are true?
0.4>0.386

28. 2 x 3 = 6
29. Write the following decimal numbers as rationals.
1.15

30. Find $\frac { -5 }{ 8 } \times 7$

31. 2 x 5 = 10
32. Simplify $=\frac { -12 }{ 10 } +\left( \frac { -90 }{ 15 } \right) -\left( \frac { 3 }{ 8 } \right)$

33. Simplify $\frac { 5 }{ 12 } +\frac { -5 }{ 18 } -\frac { 7 }{ 24 }$