**Exponents ICSE Class-7th Concise **Selina Maths Solutions Chapter-5. We provide step by step Solutions of Exercise / lesson-5 **Exponents** for** ICSE** **Class-7 Concise** Selina Mathematics. Our Solutions contain all type Questions with Exe-5 A and Exe-5 B, to develop skill and confidence. Visit official Website **CISCE** for detail information about ICSE Board Class-7.

**Exponents ICSE Class-7th Concise **Selina Maths Solutions Chapter-5

**–: Select Topics :–**

### Exercise – 5 A **Exponents ICSE Class-7th Concise **Selina Maths Solutions

**Question 1 :-**

Find the value of:

(i) 6²

(ii) 7^{3}

(iii) 4^{4}

(iv) 5^{5}

(v) 8^{3}

(vi) 7^{5
}**Answer :-**

**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
}

**Answer :-**

**Question 3 :-**

**Evaluate:**

**Answer :-**

**Question 4 :-**

Evaluate :

**Answer :-**

**Question 5 :-**

Which is greater :

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

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

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

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

**Answer :-**

**Question 6 :-**

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

(i) 512

(ii) 1250

(iii) 1458

(iv) 3600

(v) 1350

(vi) 1176

**Answer :-**

**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}

**Answer :-**

**Question 8 :-**

Express:

(i) 1024 as a power of 2.

(ii) 343 as a power of 7.

(iii) 729 as a power of 3.

**Answer :-**

**Question 9 :-**

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

**Answer :-**

**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
}

**Answer :-**

### Exercise – 5 B **Exponents ICSE Class-7th Concise Selina Mathematics**

**Question 1 :-**

Fill in the blanks:

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

(ii) If index = 3x and base = 2y, the number = ………

**Answer :-**

**(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
}

**Answer :-**

**Question 3 :-**

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

**Answer :-**

**(xvii)**

(2a^{3})^{4} (4a^{2})^{2}

= (2a^{3})^{4} (2^{2}a^{2})^{2}

= 2^{4} a^{3×4} . 2^{2×2} a^{2×2}

= 2^{4}a^{12} . 2^{4}a^{4}

= 2^{4+4} a^{12+4}

= 2^{8}a^{16}

= 2 × 2 × 2 × 2 × 2 × 2 × 2 × 2 × a^{16}

= 256 a^{16}

**(xviii)**

^{2}y

^{3})

^{3}÷ (3x

^{2}y

^{3})

^{3}

**(xix)**

**Question 4 :-**

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

**Answer :-**

**(i)**

**(ii) **

**(iii)**

**(iv)**

**-128/2187**

2 | 128 |

2 | 64 |

2 | 32 |

2 | 16 |

2 | 8 |

2 | 4 |

2 | 2 |

1 |

3 | 2187 |

3 | 729 |

3 | 243 |

3 | 81 |

3 | 27 |

3 | 9 |

3 | 3 |

1 |

**(v) **

**(vi) **

**Question 5 :-**

Evaluate

**Answer :-**

**(iii)**

5^{3} × 3^{2} + (17)^{0} × 7^{3}

= 5 × 5 × 5 × 3 × 3 + (17)^{0} × 7 × 7 × 7 (∵ a^{0} = 1)

= 125 × 9 + 1 × 343

= 1125 + 343 = 1468

**(iv) **

**(v)**

**= 1 + 4 + 8 = 13**

**(vi) **

**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

**Answer :-**

**(iii)**

6m^{-3} + 4n^{2}

m = – 2, n =2

= 6(-2)^{-3} + 4(2)^{2}

**(iv)**

2n^{3} – 3m

m = -2, n = 2

= 2(2)^{3} – 3(-2)

= 2 × (2 × 2 × 2) – 3 × (- 2)

= 16 – 3 × (-2)

= 16 + 6 = 22

— End of **Exponents** Solutions :–

Return to **– Concise Selina Maths Solutions for ICSE Class -7 **

Thanks