Rational Numbers (Mathematics) Class 8 - NCERT Questions

Q 1.

Using appropriate properties, find.

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Q 2.

Write the additive inverse of each of the following.

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Q 3.

Verify that –(–x) = x for
(i) x = 11/15 (ii) x = −13/17.

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Q 4.

Find the multiplicative inverse of the following.

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Q 5.

Name the property under multiplication used in each of the following.

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Q 6.

Multiply 6/13 by the reciprocal of −7/16

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Q 7.

Tell what property allows you to compute

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Q 8.

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Q 9.

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Q 10.

Write.
(i) The rational number that does not have a reciprocal.
(ii) The rational numbers that are equal to their reciprocals.
(iii) The rational number that is equal to its negative.

SOLUTION:

(i) 0 is the rational number, which does not have a reciprocal.
(ii) 1 and (–1) are the rational numbers, that are equal to their reciprocals.
(iii) 0 is the rational number that is equal to its negative.

Q 11.

Fill in the blanks.
(i) Zero has ........... reciprocal.
(ii) The numbers ......... and ......... are their own reciprocals.
(iii) The reciprocals of –5 is ............. .
(iv) Reciprocal of 1x, where x ≠ 0 is ......... .
(v) The product of two rational numbers is always a ......... .
(vi) The reciprocal of positive rational number is ........... .

SOLUTION:

(i) Zero have no reciprocal.
(ii) The numbers 1 and –1 are their own reciprocals.
(iii) The reciprocal of –5 is −1/5.
(iv) Reciprocal of 1/x, where x ≠ 0 is x.
(v) The product of two rational numbers is always a rational number.
(vi) The reciprocal of a positive rational number is positive.

Q 12.

Represent these numbers on the number line.
(i) 7/4 (ii) −5/6

SOLUTION: