NCERT Solutions for Class 7 Maths Chapter 9 Rational Numbers Exercise 9.2

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Chapter 9 : Rational Numbers

# Chapter Explanation & Overview
# NCERT Exercise 9.1 Solutions
# NCERT Exercise 9.2 Solutions
# Extra Questions with Solutions
# Multiple Choice Questions
# Fill In The Blanks
# True / False
# Test

NCERT Solutions for Class 7 Maths Chapter 9 Rational Numbers Exercise 9.2

Question 1... Class 7 Maths Ex.9.2

Find the sum:

(i) 5/4 + (-11/4)

Explanation :

Given rational numbers are

⇒ 5/4 and -11/4

As we have same denominator in both the Rational Number

So, we just need to add the numerators

⇒ [5+ (-11)] /4

⇒ -6/4

Now, Divide both numerator and denominator by 2

Ans. -3/2

Write your Solution like this

Solution :

(ii) 5/3 + (3/5)

Explanation :

Given rational numbers are

⇒ 5/3 and 3/5

First we need to make both the denominator equal

for this, we need to find LCM

# LCM of 3 and 5 is 15

Now,

⇒ (5/3) = [(5×5)/ (3×5)] = (25/15)

⇒ (3/5) = [(3×3)/ (5×3)] = (9/15)

Then, add the numerators

⇒ (25/15) + (9/15)

⇒ (25 + 9)/15

Ans. 34/15

Write your Solution like this

Solution :

(iii) -9/10 + 22/15

Explanation :

Given rational numbers are

⇒ -9/10 and 22/15

First we need to make both the denominator equal

for this, we need to find LCM

# LCM of 10 and 15 is 30

Now,

⇒ (-9/10) = [(-9×3)/ (10×3)] = (-27/30)

⇒ (22/15) = [(22×2)/ (15×2)] = (44/30)

Then, add the numerators

⇒ (-27/30) + (44/30)

⇒ (-27 + 44)/30

Ans. (17/30)

Write your Solution like this

Solution :

(iv) -3/11 + 5/9

Explanation :

Given rational numbers are

⇒ -3/11 and 5/9

First we need to make both the denominator equal

for this, we need to find LCM

# LCM of 11 and 9 is 99

Now,

⇒ (3/11)= [(3×9)/ (11×9)] = (27/99)

⇒ (5/9)= [(5×11)/ (9×11)] = (55/99)

Then, add the numerators

⇒ (27/99) + (55/99)

⇒ (27 + 55)/99

Ans. (82/99)

Write your Solution like this

Solution :

(v) -8/19 + (-2/57)

Explanation :

Given rational numbers are

⇒ -8/19 and -2/57

First we need to make both the denominator equal

for this, we need to find LCM

# LCM of 19 and 57 is 57

Now,

⇒ (-8/19)= [(-8×3)/ (19×3)] = (-24/57)

⇒ (-2/57)= [(-2×1)/ (57×1)] = (-2/57)

Then, add the numerators

⇒ (-24/57) + (-2/57)

⇒ (-24 - 2)/57

Ans. (-26/57)

Write your Solution like this

Solution :

(vi) -2/3 + 0

Explanation :

Given rational numbers are

⇒ -2/3 and 0

We know that when a number is added to zero the answer will be the same number.

Hence,

⇒ -2/3 + 0

⇒ -2/3

Ans. (-2/3)

Write your Solution like this

Solution :

(vii)

Explanation :

First we need to convert mixed fraction into improper fraction

⇒ (-3x2+1) /3 = -7/3

and

⇒ (5x4+3) /5 = 23/5

Now, make both the denominator equal by taking LCM

# LCM of 3 and 5 is 15

Now,

⇒ (-7/3)= [(-7×5)/ (3×5)] = (-35/15)

⇒ (23/5)= [(23×3)/ (15×3)] = (69/15)

Then, add the numerators

⇒ (-35/15) + (69/15)

⇒ (-35 + 69)/15

Ans. (34/15)

Write your Solution like this

Solution :

Question 2... Class 7 Maths Ex.9.2

Find :

(i) (7/24) - (17/36)

Explanation :

Given rational numbers are

⇒ 7/24 - (17/36)

First we need to make both the denominator equal for this, we need to find LCM

# LCM of 24 and 36 is 72

Now,

⇒ (7/24) = [(7×3)/ (24×3)] = (21/72)

⇒ (17/36)= [(17×2)/ (36×2)] = (34/72)

Then, Subtract the numerators

⇒ (21/72) – (34/72)

⇒ (21 – 34)/72

Ans. (-13/72)

Write your Solution like this

Solution :

(ii) (5/63) - (-6/21)

Explanation :

Given rational numbers are

⇒ (5/63) - (-6/21)

First we need to make both the denominator equal for this, we need to find LCM

# LCM of 63 and 21 is 63

Now,

⇒ (5/63) = [(5×1)/ (63×1)] = (5/63)

⇒ (-6/21) = [(-6×3)/ (21×3)] = (-18/63)

Then, Subtract the numerators

⇒ (5/63) - (-18/63)

⇒ (5 + 18)/63

Ans. 23/63

Write your Solution like this

Solution :

(iii) (-6/13) - (-7/15)

Explanation :

Given rational numbers are

⇒ -6/13 and -7/15

First we need to make both the denominator equal for this, we need to find LCM

# LCM of 13 and 15 is 195

Now,

⇒ (-6/13) = [(-6×15)/ (13×15)] = (-90/195)

⇒ (7/15) = [(-7×13)/ (15×13)] = (-91/195)

Then, subtract the numerators

⇒ (-90/195) + (-91/195)

⇒ (-90 - (-91)/57

Ans. (1/195)

Write your Solution like this

Solution :

(iv) (-3/8) - (7/11)

Explanation :

Given rational numbers are

⇒ -3/8 and 7/11

First we need to make both the denominator equal for this, we need to find LCM

# LCM of 8 and 11 is 88

Now,

⇒ (-3/8)= [(-3×11)/ (8×11)] = (-33/88)

⇒ (7/11)= [(7×8)/ (11×8)] = (56/88)

Then, Subtract the numerators

⇒ (-33/88) – (56/88)

⇒ (-33 – 56)/88

Ans. (-89/88)

Write your Solution like this

Solution :

(v)

Explanation :

First we need to convert this mixed fraction into improper fraction

⇒ (-9x2+1) = -19/9

And,

⇒ 6 = 6/1

Then, make both the denominator equal for this, we need to find LCM

# LCM of 9 and 1 is 9

Now,

⇒ (-19/9)= [(-19×1)/ (9×1)] = (-19/9)

⇒ (6/1)= [(6×9)/ (1×9)] = (54/9)

Then, Subtract the numerators

⇒ (-19/9) – (54/9)

⇒ (-19 – 54)/9

Ans. (-73/9)

Write your Solution like this

Solution :

Question 3... Class 7 Maths Ex.9.2

Find the Product :

(i) (9/2) x (-7/4)

Explanation :

The product of two rational numbers are the (product of their numerator) / (product of their denominator)

We have,

⇒ (9/2) x (-7/4)

So,

⇒ (9×-7)/ (2×4)

Ans. -63/8

Write your Solution like this

Solution :

(ii) (3/10) x (-9)

Explanation :

The product of two rational numbers are the (product of their numerator) / (product of their denominator)

We have,

⇒ (3/10) x (-9/1)

So,

⇒ (3×-9)/ (10×1)

Ans. -27/10

Write your Solution like this

Solution :

(iii) (-6/5) x (9/11)

Explanation :

The product of two rational numbers are the (product of their numerator) / (product of their denominator)

We have,

⇒ (-6/5) x (9/11)

So,

⇒ (-6×9)/ (5×11)

Ans. -54/55

Write your Solution like this

Solution :

(iv) (3/7) x (-2/5)

Explanation :

The product of two rational numbers are the (product of their numerator) / (product of their denominator)

We have,

⇒ (3/7) x (-2/5)

So,

⇒ (3×-2)/ (7×5)

Ans. -6/35

Write your Solution like this

Solution :

(v) (3/11) x (2/5)

Explanation :

The product of two rational numbers are the (product of their numerator) / (product of their denominator)

We have,

⇒ (3/11) x (2/5)

So,

⇒ (3×2)/ (11×5)

Ans. 6/55

Write your Solution like this

Solution :

(vi) (3/-5) x (-5/3)

Explanation :

The product of two rational numbers are the (product of their numerator) / (product of their denominator)

We have,

⇒ (3/-5) x (-5/3)

So,

⇒ (3×-5)/ (-5×3)

⇒ -15/-15

Ans. 1

Write your Solution like this

Solution :

Question 4... Class 7 Maths Ex.9.2

Find the value of :

(i) (-4) ÷ (2/3)

Explanation :

To Divide two Rational Numbers we just need to reciprocal the second one

Then just find (product of their numerator) / (product of their denominator)

Here we have,

⇒ (-4/1) ÷ (2/3)

So,

⇒ (-4/1) x (3/2)

⇒ (-4x3) / (1x2)

⇒ -12/2

Ans. -6

Write your Solution like this

Solution :

(ii) (-3/5) ÷ (2)

Explanation :

To Divide two Rational Numbers we just need to reciprocal the second one

Then just find (product of their numerator) / (product of their denominator)

Here we have,

⇒ (-3/5) ÷ (2/1)

So,

⇒ (-3/5) x (1/2)

⇒ (-3x1) / (5x2)

Ans. -3/10

Write your Solution like this

Solution :

(iii) (-4/5) ÷ (-3)

Explanation :

To Divide two Rational Numbers we just need to reciprocal the second one

Then just find (product of their numerator) / (product of their denominator)

Here we have,

⇒ (-4/5) ÷ (-3/1)

So,

⇒ (-4/5) x (1/-3)

⇒ (-4x1) / (5x-3)

⇒ -4/-15

Ans. 4/15

Write your Solution like this

Solution :

(iv) (-1/8) ÷ (3/4)

Explanation :

To Divide two Rational Numbers we just need to reciprocal the second one

Then just find (product of their numerator) / (product of their denominator)

Here we have,

⇒ (-1/8) ÷ (3/4)

So,

⇒ (-1/8) x (4/3)

⇒ (-1x4) / (8x3)

⇒ -4/24

Ans. -1/6

Write your Solution like this

Solution :

(v) (-2/13) ÷ (1/7)

Explanation :

To Divide two Rational Numbers we just need to reciprocal the second one

Then just find (product of their numerator) / (product of their denominator)

Here we have,

⇒ (-2/13) ÷ (1/7)

So,

⇒ (-2/13) x (7/1)

⇒ (-2x7) / (13x1)

Ans. -14/13

Write your Solution like this

Solution :

(vi) (-7/12) ÷ (-2/13)

Explanation :

To Divide two Rational Numbers we just need to reciprocal the second one

Then just find (product of their numerator) / (product of their denominator)

Here we have,

⇒ (-7/12) ÷ (-2/13)

So,

⇒ (-7/12) x (13/-2)

⇒ (-7x13) / (12x-2)

⇒ -91/-24

Ans. 91/24

Write your Solution like this

Solution :

(vii) (3/13) ÷ (-4/65)

Explanation :

To Divide two Rational Numbers we just need to reciprocal the second one

Then just find (product of their numerator) / (product of their denominator)

Here we have,

⇒ (3/13) ÷ (-4/65)

So,

⇒ (3/13) x (65/-4)

⇒ (3x65) / (13x-4)

⇒ 195/-52

Ans. -15/4

Write your Solution like this

Solution :

Chapter 9 : Rational Numbers

# Chapter Explanation & Overview
# NCERT Exercise 9.1 Solutions
# NCERT Exercise 9.2 Solutions
# Extra Questions with Solutions
# Multiple Choice Questions
# Fill In The Blanks
# True / False
# Test

# Still have some Doubts?

--Feel Free to ask your Doubts here--

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NCERT Solutions for Class 7 Maths Chapter 9 Rational Numbers Exercise 9.2

NCERT Solutions for Class 7 Maths Chapter 9 Rational Numbers Exercise 9.2

Question 1... Class 7 Maths Ex.9.2

Question 2... Class 7 Maths Ex.9.2

Question 3... Class 7 Maths Ex.9.2

Question 4... Class 7 Maths Ex.9.2

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