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 the reciprocal of -4.
  • A
    -4
  • B
    \(\frac{{ - 1}}{4}\)
    Correct
  • C
    4
  • D
    none of these
2
Write the additive inverse of\(\frac{5}{6}\).
  • A
    \( - \frac{5}{6}\)
    Correct
  • B
    0
  • C
    1
  • D
    \(\frac{5}{6}\)
3
Write the additive inverse of\(\frac{7}{8}\).
  • A
    0
  • B
    \(\frac{7}{8}\)
  • C
    1
  • D
    \( - \frac{7}{8}\)
    Correct
4
Find the multiplicative inverse of -15.
  • A
    \(\frac{{ - 1}}{{15}}\)
    Correct
  • B
    -15
  • C
    15
  • D
    14
5
Name the property under multiplication used in\(\frac{{ - 1}}{3} \times ( - 3) = - 3 \times \frac{{ - 1}}{3} = 1\).
  • A
    none of thes Multiplicative identity e
  • B
    Commutative property
  • C
    Associative property
  • D
    Reciprocal
    Correct
6
Name the property under multiplication used in\(\frac{{ - 1}}{3} \times ( - 3) = 1\).
  • A
    none of these
  • B
    Associative property
  • C
    Multiplicative identity
    Correct
  • D
    Commutative property
7
Sum of two _________ is a rational number.
  • A
    none of these
  • B
    negative numbers
  • C
    rational numbers
    Correct
  • D
    irrational numbers
8
For any three rational numbers x, y and z, x + (y + z) = __________.
  • A
    (x + y) - z
  • B
    (x - y) + z
  • C
    (x - y) - z
  • D
    (x + y) + z
    Correct
9
_______ = a for any rational number a.
  • A
    \(a \times {\text{ }}0\)
  • B
    \(a \times {\text{ 2}}\)
  • C
    \(a \times {\text{ 3}}\)
  • D
    \(a \times {\text{ 1}}\)
    Correct
10
Find \(\frac{3}{7} + \left( { - \frac{5}{{14}}} \right) + \left( { - \frac{8}{{21}}} \right) + \frac{5}{{21}}\)
  • A
    -1
  • B
    \(\frac{{ - 1}}{{21}}\)
    Correct
  • C
    -21
  • D
    1
11
Find \(\frac{3}{4} + \left( { - \frac{5}{2}} \right) + \left( { - \frac{8}{3}} \right) + \frac{5}{5}\)
  • A
    -1
  • B
    -41
  • C
    12
  • D
    \( - \frac{{41}}{{12}}\)
    Correct
12
Find \(\frac{5}{7} + \left( { - \frac{6}{7}} \right) + \left( { - \frac{8}{{35}}} \right) + \frac{5}{{21}}\)
  • A
    \(\frac{{ - 11}}{{105}}\)
    Correct
  • B
    -11
  • C
    105
  • D
    -105
13
Find \(\frac{3}{5} + \left( { - \frac{5}{{12}}} \right) + \left( { - \frac{7}{{15}}} \right) + \frac{5}{{20}}\)
  • A
    30
  • B
    30
  • C
    -1
  • D
    \(\frac{{ - 1}}{{30}}\)
    Correct
14
Find \(\frac{7}{8} + \left( { - \frac{5}{{16}}} \right) + \left( { - \frac{3}{{16}}} \right) + \frac{5}{8}\)
  • A
    -21
  • B
    -1
  • C
    1
    Correct
  • D
    -16
15
Find \(\frac{5}{9} + \left( { - \frac{5}{{18}}} \right) + \left( { - \frac{7}{{18}}} \right) + \frac{7}{9}\)
  • A
    -2
  • B
    3
  • C
    \(\frac{2}{3}\)
    Correct
  • D
    -3