Class 8 Rational Numbers CBSE Questions & Answers

Class 8 · Rational Numbers

This is Mathematics Class 8 Rational Numbers CBSE Questions & Answers. There are 15 questions in this test with each question having around four answer choices.

Questions & Answers

1
Find: \(\frac{2}{5} \times \frac{{ - 3}}{7} - \frac{1}{{14}} - \frac{3}{7} \times \frac{3}{5}\)
  • A
    \(\frac{1}{2}\)
  • B
    \( - \frac{1}{2}\)
    Correct
  • C
    2
  • D
    1
2
Write the rational number that does not have a reciprocal.
  • A
    -1
  • B
    2
  • C
    0
    Correct
  • D
    1
3
Write the additive inverse of\(\frac{9}{8}\).
  • A
    0
  • B
    1
  • C
    \( - \frac{9}{8}\)
    Correct
  • D
    \(\frac{9}{8}\)
4
\(0{\text{ }} \times {\text{ }}\frac{1}{4}{\text{ }} = {\text{ }}\_\_\_\_\_\_\_\)
  • A
    1
  • B
    \(\frac{1}{4}\)
  • C
    4
  • D
    0
    Correct
5
Find the multiplicative inverse of\( - \frac{9}{{13}}\).
  • A
    \( - \frac{9}{{13}}\)
  • B
    \( - \frac{{13}}{9}\)
    Correct
  • C
    \(\frac{{13}}{9}\)
  • D
    \(\frac{9}{{13}}\)
6
Name the property under multiplication used in\(\frac{3}{5} \times \frac{7}{2} = \frac{7}{2} \times \frac{3}{5}\).
  • A
    Multiplicative identity
  • B
    Commutative property
    Correct
  • C
    Associative property
  • D
    None of these
7
A number which can be written in the form _____, where p and q are integers and \(q \ne {\text{ }}0\)is called a rational number.
  • A
    p – q
  • B
    \(\frac{p}{q}\)
    Correct
  • C
    \(p{\text{ }} \times {\text{ }}q\)
  • D
    p + q
8
For any two rational numbers a and b, a + b = _________.
  • A
    \(b{\text{ }} \times {\text{ }}a\)
  • B
    b - a
  • C
    \(b{\text{ }} \div {\text{ }}a\)
  • D
    b + a
    Correct
9
For any three rational numbers a, b and \(c,a \times {\text{ }}\left( {b \times c} \right){\text{ }} = {\text{ }}\_\_\_\_\_\_\_\_\_.\)
  • A
    \(\left( {a + b} \right){\text{ }} - c\)
  • B
    \(\left( {a \times b} \right){\text{ }} - c\)
  • C
    \(\left( {a \times b} \right){\text{ }} + c\)
  • D
    \(\left( {a \times b} \right){\text{ }} \times c\)
    Correct
10
Reciprocal of\(\frac{1}{x}\), where \(x \ne {\text{ }}0\) is ________.
  • A
    \(\frac{1}{x}\)
  • B
    0
  • C
    1
  • D
    x
    Correct
11
Tell what property allows you to compute \(\frac{1}{3} \times \left( {6 \times \frac{4}{3}} \right)as\left( {\frac{1}{3} \times 6} \right) \times \frac{4}{3}\)
  • A
    none of these
  • B
    Associative property of multiplication
    Correct
  • C
    Commutative property of multiplication
  • D
    Associative property of addition
12
Write the rational numbers that are equal to their reciprocals.
  • A
    1, -1
    Correct
  • B
    2, -2
  • C
    none of these
  • D
    0
13
\(0{\text{ }} \times {\text{ }}\frac{1}{2}{\text{ }} = {\text{ }}\_\_\_\_\)
  • A
    2
  • B
    \(\frac{1}{2}\)
  • C
    1
  • D
    0
    Correct
14
Write the additive inverse of\(\frac{{12}}{{11}}\).
  • A
    \( - \frac{{12}}{{11}}\)
    Correct
  • B
    \(\frac{{12}}{{11}}\)
  • C
    1
  • D
    0
15
Find the multiplicative inverse of 25.
  • A
    \(\frac{1}{{25}}\)
    Correct
  • B
    -25
  • C
    24
  • D
    25