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 multiplicative inverse of\(\frac{{ - 1}}{{21}}\).
  • A
    -22
  • B
    21
  • C
    \(\frac{{ - 1}}{{21}}\)
  • D
    -21
    Correct
2
Write the additive inverse of\(\frac{{16}}{{19}}\).
  • A
    \(\frac{{16}}{{19}}\)
  • B
    1
  • C
    \( - \frac{{16}}{{19}}\)
    Correct
  • D
    0
3
Find the multiplicative inverse of -23.
  • A
    23
  • B
    24
  • C
    -23
  • D
    \(\frac{{ - 1}}{{23}}\)
    Correct
4
\(\frac{{15}}{{17}} + \left( { - \frac{{15}}{{17}}} \right) = {\text{ }}\_\_\_\_\)
  • A
    17
  • B
    15
  • C
    1
  • D
    0
    Correct
5
\(\left( { - \frac{{16}}{{19}}} \right) + \frac{{16}}{{19}} = {\text{ }}\_\_\_\_\)
  • A
    1
  • B
    16
  • C
    19
  • D
    0
    Correct
6
\( - \frac{2}{5} \times \left( { - \frac{5}{2}} \right) = {\text{ }}\_\_\_\_\)
  • A
    5
  • B
    1
    Correct
  • C
    \(\frac{2}{5}\)
  • D
    2
7
\( - \frac{{17}}{{18}} \times \left( { - \frac{{18}}{{17}}} \right) = {\text{ }}\_\_\_\_\)
  • A
    1
    Correct
  • B
    18
  • C
    17
  • D
    \(\frac{{18}}{{17}}\)
8
\( - \frac{{19}}{{21}} \times \left( { - \frac{{21}}{{19}}} \right) = {\text{ }}\_\_\_\_\)
  • A
    19
  • B
    21
  • C
    \(\frac{{19}}{{21}}\)
  • D
    1
    Correct
9
\(\frac{{18}}{{23}} + \left( { - \frac{{18}}{{23}}} \right) = {\text{ }}\_\_\_\_\)
  • A
    0
    Correct
  • B
    18
  • C
    23
  • D
    \(\frac{{18}}{{23}}\)
10
\(\frac{{13}}{{19}} + \left( { - \frac{{13}}{{19}}} \right) = {\text{ }}\_\_\_\_\)
  • A
    0
    Correct
  • B
    13
  • C
    19
  • D
    \( - \frac{{13}}{{19}}\)
11
Find \( - \frac{2}{3} \times \frac{3}{5} + \frac{5}{2} - \frac{3}{5} \times \frac{1}{6}\)
  • A
    2
    Correct
  • B
    -3
  • C
    -2
  • D
    3
12
Find \(\frac{2}{5} \times \left( { - \frac{3}{7}} \right) - \frac{1}{6} \times \frac{3}{2} + \frac{1}{{14}} \times \frac{2}{5}\)
  • A
    \( - \frac{{11}}{{28}}\)
    Correct
  • B
    28
  • C
    -28
  • D
    -11
13
Find \(\frac{3}{7} + \left( { - \frac{5}{{14}}} \right) + \left( { - \frac{9}{{14}}} \right) + \frac{5}{7}\)
  • A
    7
  • B
    \(\frac{1}{7}\)
    Correct
  • C
    -7
  • D
    -1
14
Find \(\frac{{11}}{{12}} + \left( { - \frac{5}{6}} \right) + \left( { - \frac{7}{6}} \right) + \frac{7}{{12}}\)
  • A
    -1
  • B
    -2
  • C
    \( - \frac{1}{2}\)
    Correct
  • D
    1
15
Find \(\frac{7}{8} + \left( { - \frac{5}{{16}}} \right) + \left( { - \frac{9}{{16}}} \right) + \frac{5}{8}\)
  • A
    -5
  • B
    \(\frac{5}{8}\)
    Correct
  • C
    8
  • D
    -8