Write the additive inverse of 3 8 and multiply it with the multiplicative inverse of - 9 4 .

Given, The additive inverse of a number “a” is the number that when added to “a”, gives the result zero. The multiplicative inverse of a fraction: a b i s b a . The additive inverse of 3 8 ⇒ - 8 3 The multiplicative inverse of - 9 4 ⇒ 4 - 9 Let's multiply the results ⇒ - 8 3 × 4 - 9 ⇒ 8 3 × 4 9 ⇒ 32 27 Hence, this is the required answer.

Simplify: - 6 16 × 8 9

Given, - 6 16 × 8 9 Reduce the expression by performing the division operation. ⇒ - 6 2 × 1 9 ⇒ - 2 2 × 1 3 ⇒ - 1 3 Hence, this is the required answer.

Find the value of the following: - 11 5 + 3 - 20

Given, - 11 5 + 3 - 20 ⇒ - 11 × - 4 + 3 - 20 ⇒ 44 + 3 - 20 ⇒ 47 - 20 ⇒ 47 20 Hence, this is the required answer.

Find five rational numbers between 3 5 & 5 6 .

Given, 3 5 & 5 6 Let's make the same denominators and solve, ⇒ 3 5 × 6 6 ⇒ 18 30 And ⇒ 5 6 × 5 5 = 25 30 Now arrange the rational numbers, ⇒ 19 30 , 20 30 , 21 30 , 22 30 & 23 30 Hence, this is the required answer.

If p q is any rational number where q ≠ 0 , then prove that p q × p q - 1 = 1 .

Given, If p q is any rational number where q ≠ 0 , we need to prove that p q × p q - 1 = 1 . Let a number ‘ r ’ is said to be a rational number, if it can be represented in the form p q , where p and q are integers and q ≠ 0 . From the given expression we have, ⇒ p q × p q - 1 = 1 ⇒ p q × 1 p q = 1 ⇒ 1 = 1 Hence, proved.

Divide - 3 14 b y 9 7 .

Given, - 3 14 b y 9 7 ⇒ - 3 14 ÷ 9 7 Reduce the expression by performing the division operation. ⇒ - 1 2 ÷ 3 1 ⇒ - 1 6 Hence, this is the required answer.

What should be added to - 3 11 to get 2 ? .

Let's subtract - 3 11 f r o m 2 ⇒ - 3 11 - 2 ⇒ - 3 - 22 11 ⇒ - 25 11 We need to add 25 11 in - 3 11 to get 2 .

What should to subtracted from 7 8 to get 1 ? .

Let's Subtract the given terms, ⇒ 7 8 - 1 ⇒ 7 - 8 8 ⇒ - 1 8 Hence, this is the required answer.

E M B I B E

Math Sight book>Chapter 1 - Rational Numbers>Mental Maths

Jharne De and Ranjana Kumar Solutions for Chapter: Rational Numbers, Exercise 1: Mental Maths

Author:Jharne De & Ranjana Kumar

Jharne De Mathematics Solutions for Exercise - Jharne De and Ranjana Kumar Solutions for Chapter: Rational Numbers, Exercise 1: Mental Maths

Attempt the practice questions on Chapter 1: Rational Numbers, Exercise 1: Mental Maths with hints and solutions to strengthen your understanding. Math Sight book solutions are prepared by Experienced Embibe Experts.