### NCERT Solutions for Class 8 Maths Chapter 1 Rational Numbers Exercise 1.1

**Ex 1.1 Class 8 Maths Question 1.**

**Using appropriate properties find:**

**Solution:**

**Ex 1.1 Class 8 Maths Question 2****.**

**Write the additive inverse of each of the following:**

**(i) 2/8 **

**(ii) -5/9**

**(iii) -6/-5**

**(iv) 2/-9**

**(v) 19/-6**

**Solution:**

**Ex 1.1 Class 8 Maths Question 3.**

**Verify that -(-x) = x for**

**(i) x = 11/5**

**(ii) x = -13/17**

**Solution:**

**Ex 1.1 Class 8 Maths Question 4.**

**Find the multiplicative inverse of the following:**

**Solution:**

**Ex 1.1 Class 8 Maths Question 5.**

**Name the property under multiplication used in each of the following:**

**Solution:**

(i) Commutative property of multiplication

(ii) Commutative property of multiplication

(iii) Multiplicative inverse property

**Ex 1.1 Class 8 Maths Question 6.**

**Multiply 6/13 by the reciprocal of -7/16.**

**Solution:**

**Ex 1.1 Class 8 Maths Question 7.**

**Tell what property allows you to compute**

**Solution:**

Since a × (b × c) = (a × b) × c shows the associative property of multiplications.

**Ex 1.1 Class 8 Maths Question 8.**

**Is 8/9 the multiplicative inverse of -1 1/8? Why or Why not?**

**Solution:**

Here -1 1/8 = -9/8.

Since multiplicative inverse of 8/9 is 9/8 but not -9/8

8/9 is not the multiplicative inverse of -1 1/8

**Ex 1.1 Class 8 Maths Question 9.**

**If 0.3 the multiplicative inverse of 3 1/3? Why or why not?**

**Solution:**

Multiplicative inverse of 0.3 or 3/10is 10/3.

Thus, 0.3 is the multiplicative inverse of 3 1/3.

**Ex 1.1 Class 8 Maths Question 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 its reciprocal

[∵1/0 is not defined]

(ii) Reciprocal of 1 = 1/1= 1

Reciprocal of -1 = 1/-1= -1

Thus, 1 and -1 are the required rational numbers.

(iii) 0 is the rational number which is equal to its negative.

**Ex 1.1 Class 8 Maths Question 11.**

**Fill in the blanks.**

**(i) Zero has ……….. reciprocal.**

**(ii) The numbers ……….. and ……….. are their own reciprocals.**

**(iii) The reciprocal of -5 is ………**

**(iv) Reciprocal of 1/x, where x ≠ 0 is ……….**

**(v) The product of two rational numbers is always a …………**

**(vi) The reciprocal of a positive rational number is ……….**

**Solution:**

(i) no

(ii) -1 and 1

(iii) -1/5

(iv) x

(v) rational number

(vi) positive