## Selina Concise Mathematics class 7 ICSE Solutions – Exponents (Including Laws of Exponents)

ICSE SolutionsSelina ICSE SolutionsML Aggarwal Solutions

APlusTopper.com provides step by step solutions for Selina Concise ICSE Solutions for Class 7 Mathematics. You can download the Selina Concise Mathematics ICSE Solutions for Class 7 with Free PDF download option. Selina Publishers Concise Mathematics for Class 7 ICSE Solutions all questions are solved and explained by expert mathematic teachers as per ICSE board guidelines.

Selina Class 7 Maths ICSE SolutionsPhysicsChemistryBiologyGeographyHistory & Civics

**EXERCISE 5 (A)**

**Question 1.**

**Find the value of:**

** (i) 6² **

** (ii) 7 ^{3}**

**(iii) 4**

^{4}**(iv) 5**

^{5}**(v) 8**

^{3}**(vi) 7**

^{5}**Solution:**

**(i)** 6^{2} = 6 x 6 = 36

**(ii)** 7^{3} = 7 x 7 x 7 = 343

**(iii)** 4^{4} = 4 x 4 x 4 x 4 = 256

**(iv)** 5^{5}= 5 x 5 x 5 x 5 x 5 = 3125

**(v)** 8^{3} = 8 x 8 x 8 = 512

**(vi)** 7^{5 }= 7 x 7 x 7 x 7 x 7 =16807

**Question 2.**

**Evaluate:**

** (i) 2 ^{3} x 4^{2}**

**(ii) 2**

^{3}x 5^{2}**(iii) 3**

^{3}x 5^{2}**(iv) 2**

^{2}x 3^{3}**(v) 3**

^{2}x 5^{2}**(vi) 5**

^{3}x 2^{4}**(vii) 3**

^{2 }x 4^{2}**(ix) (5 x 4)**

^{2}**Solution:**

**(i)** 2^{3} x 4^{2}

= 2 x 2 x 2 x 4 x 4

= 8 x 16

= 128

**(ii)** 2^{3} x 5^{2}

= 2 x 2 x 2 x 5 x 5

= 8 x 25

= 200

**(iii)** 3^{3} x 5^{2}

=3 x 3 x 3 x 5 x 5

= 27 x 25

= 675

**(iv)** 2^{2} x 3^{3}

= 2 x 2 x 3 x 3 x 3

= 4 x 27

= 108

**(v)** 3^{2} x 5^{3}

=3 x3 x 5 x 5 x 5

= 9 x 125

= 1125

**(vi)** 5^{3} x 2^{4}

= 5 x 5 x 5 x 2 x 2 x 2 x 2

= 125 x 16

= 2000

**(vii)** 3^{2} x 4^{2}

=3 x 3 x 4 x 4

= 9 x 16

=144

**(viii)** (4 x 3)^{3}

=4 x 4 x 4 x 3 x 3 x 3

= 64 x 27

= 1728

**(ix)** (5 x 4)^{2}

=5 x 5 x 4 x 4

= 25 x 16

= 400

**Question 3.**

**Evaluate:**

**Solution:**

**Question 4.**

**Evaluate :**

**Solution:**

**Question 5.**

**Which is greater :**

** (i) 2 ^{3} or 3^{2}**

(ii) 2^{5} or 5^{2}

**(iii) 4**

(iv) 5

^{3}or 3^{4}(iv) 5

^{4}or 4^{5}**Solution:**

**(i)** 2^{3} or 3^{3}

Since, 2^{3} = 2 x 2 x 2 = 8

and, 3^{2} = 3 x 3 = 9

∵9 is greater than 8 ⇒ 3^{2} > 2^{3}

**(ii)** 2^{5} or 5^{2}

Since, 2^{5} = 2 x 2 x 2 x 2 x 2 = 32

and, 5^{2} = 5 x 5 = 25

∵32 is greater than 25 ⇒ 2^{35} > 5^{32}

**(iii)** 4^{3} or 3^{4}

Since, 4^{3} = 4 x 4 x 4 = 64

and, 3^{4} = 3 x 3 x 3 x 3 = 81

∵ 81 is greater than 64 ⇒ 3^{4} > 4^{3}

**(iv)** 5^{4} or 4^{5}

Since, 5^{4} = 5 x 5 x 5 x 5 = 625

and, 4^{5 }= 4 x 4 x 4 x 4 x 4= 1024

∵ 1024 is greater than 625 ⇒ 4^{5} > 5^{4}

**Question 6.**

**Express each of the following in exponential form :**

** (i) 512**

** (ii) 1250**

** (iii) 1458**

** (iv) 3600**

** (v) 1350**

** (vi) 1176**

**Solution:**

**(i)** 512

**(ii)** 1250

**(iii)** 1458

**(iv)** 3600

**(v)** 1350

**(vi)** 1176

**Question 7.**

**If a = 2 and b = 3, find the value of:**

** (i) (a + b) ^{2}**

**(ii) (b – a)**

^{3}**(iii) (a x b)a (iv) (a x b)b**

**Solution:**

**(i)** (a + b)^{2}

= (2 + 3)^{2} = (5)^{2} = 5 x 5 = 25

**(ii)** (b – a)^{2}

= (3 – 2)^{2}= (1)^{3}

= 1 x 1 x 1 = 1

**(iii)** (a x b)^{a}

= (2 x 3)^{2} – (6)^{2}

= 6 x 6 = 36

**(iv)** (a x b)^{b}

= (2 x 3)^{3} = (6)^{3} = 6 x 6 x 6 = 216

**Question 8.**

**Express:**

** (i) 1024 as a power of 2.**

** (ii) 343 as a power of 7.**

** (iii) 729 as a power of 3.**

**Solution:**

**(i)** 1024 as a power of 2.

**(ii)** 343 as a power of 7.

**(iii)** 729 as a power of 3.

**Question 9.**

**If 27 x 32 = 3 ^{x} x 2^{y}; find the values of x and y.**

**Solution:**

**Question 10.**

**If 64 x 625 = 2 ^{a} x 5^{b}; find :**

**(i) the values of a and b.**

**(ii) 2**

^{b}x 5^{a}**Solution:**

**(i)** the values of a and b.

**(ii)** 2^{b} x 5^{a}

**EXERCISE 5 (B)**

**Question 1.**

**Fill in the blanks:**

** In 5 ^{2} = 25, base = ……… and index = ……….**

**If index = 3x and base = 2y, the number = ………**

**Solution:**

**(i)** In 5^{2} = 25, base = 5 and index = 2

**(ii)** If index = 3x and base = 2y, the number = 2y^{3x}

**Question 2.**

**Evaluate:**

** (i) 2 ^{8} ÷ 2^{3}**

**(ii) 2**

^{3÷}2^{8}**(iii) (2**

^{6})^{0}**(iv) (3**

^{o})^{6}**(v) 8**

^{3}x 8^{-5}x 8^{4}**(vi) 5**

^{4 }x 5^{3}+ 5^{5}**(vii) 5**

^{4}÷ 5^{3}x 5^{5}**(viii) 4**

^{4}÷ 4^{3}x 4^{0}**(ix) (3**

^{5}x 4^{7}x 5^{8})^{0}**Solution:**

**Question 3.**

**Simplify, giving Solutions with positive index:**

**Solution:**

**Question 4.**

**Simplify and express the Solution in the positive exponent form :**

**Solution:**

**Question 5.**

**Evaluate**

**Solution:**

**Question 6.**

**If m ^{2} = -2 and n = 2; find the values of:**

**(i) m + r**

^{2}– 2mn**(ii) m**

^{n}+ n^{m}**(iii) 6m**

^{-3}+ 4n^{2}**(iv) 2n**

^{3}– 3m**Solution:**

T says

Good

zeesh says

Hello

This is a good idea for a guide for a book but you should make a book or a app

And another thing is that there is no option for downloading PDF

Shaminder says

It is very nice for maths. Studentwe can easily find any maths solution.it was very helpful for me

Mystery man says

The my friend

Mystery man says

You are a great man who helps other

Priya says

It is good but lots of typing error r in the question and answers

Anushka says

It is very nice my exam was very nice as I have practiced these question

Abul Kh@n B@b@ P@th@n says

Abe kuch samjhao bhi to bekar hai Maths Aati nhi kya ?????