# Maths Wiz Solutions Class 8 Chapter 2

## Maths Wiz Class 8 Solutions Chapter 2 Powers (Exponents)

Welcome to NCTB Solutions. Here with this post we are going to help 8th class students for the Solutions of Maths Wiz Class 8 Math Book, Chapter 2, Powers (Exponents). Here students can easily find step by step solutions of all the problems for Powers (Exponents), Exercise 2A and 2B Also here our mathematics teacher’s are solved all the problems with easily understandable methods with proper guidance so that all the students can understand easily. Here in this post students will get chapter 2 solutions. Here in this post all the solutions are based on ICSE latest Syllabus.

Powers (Exponents) Exercise 2A Solution :

Question no – (1)

Solution :

(a) 90

= 1

(b) (1/3)0

= 1

(c) (- 3 1/21)0

= 1

(d) (395.008)0

= 1

(e) (3xy/ab – z)0

= 1

(f) 1/a0 + b0 + c0

= 1/1 + 1 + 1

= 1/3

(g) (80 – 20) × 250

= (1 – 1) × 1

= 0

(h) (350 + 20 + 30) ÷ 3

= 3 ÷ 3

= 1

Question no – (2)

Solution :

(a) 6-1

= 1/6

(b) 10-1

= 1/10

(c) 4-3

= 1/43

= 1/64

(e) 3-3

= 1/33

= 1/27

(f) p-1

= 1/p

(g) (x-2)2

= 1/x4

(h) (10a)-2

= 1/(10a)2

(i) (x + y)-2

= 1/(x + y)2

(j) (m5)-3

= 1/m15

Question no – (3)

Solution :

(a) (3)-2

= 1/32

= 1/9

(b) (-2)-5

= 1/(-2)5

= – 1/32

(c) (2/5)-3

= 1/(2/5)3

= 25/4

(d) (2/3)-4

= (2/3)-4

= (3/4)4

Question no – (4)

Solution :

(a) (- 2)-4 × (- 2)-6

= 1/24 × 1/26

= 1/210

(b) 37 × 3-9 × 36

= 37 × 36/39

= 34

(c) 3× (3/5)-7

= 37 × (5/3)7

= 57

(d) 2-7 × [(2)-3]-4

= 27 × 212

= 219

Question no – (5)

Solution :

(a) (80 + 5-1) × (1/5)-2

= (1 + 1/5) × 52

= 6/5 × 52

= 6 × 5

= 30

(b) (300 + 150) × (1/2)-3

= (1 + 1) × 23

= 21 × 23

= 24

(c) (7-1 + 8-1 + 9-1)0 ÷ (- 1/9)-2

= (1/7 + 1/8 + 1/9) ÷ 92

= 1 × 9-2

= 1/81

(d) [(1/3)-2 + (1/4)-2 + (1/6)-2]

= [3+ 42 + 62]

= 9 + 16 + 36

= 51

(e) {(-4/5)-2}-2

= {(5/4)2}-2

= (5/4)-4

= (4/5)4

(f) 9-1 × 43/3-4

= 43 × 34/9

= 43 × 9 × 32/9

= 43 × 32

(g) (5-1 × 4-1) × (3/2)-2

= (1/5 × 1/4) (2/3)2

= 1/20 × 4/9

= 1/45

Question no – (6)

Solution :

(a) [(1/4)-1 – (1/5)-1] + 1

= [4 + 5] + 1

= 9 + 1

= 10

(b) [(11/12)-10 ÷ (11/12)-12] × 1 23/121

= [(12/11)10 ÷ (12/11)12] × 144/121

= [(12/11)10 × (11)12/(12)12 × 122/112

= 112/122 × 122/112

= 1

Question no – (7)

Solution :

Given, 72m/7 – 4 = 7-6

= 72m × 74 = 7-6

= 72m + 4 = 7-6

= 72m+4 = 7–6

So, 2m + 4 = – 6

= 2m = – 10

= m = – 5

Therefore, the value of m will be -5

Powers (Exponents) Exercise 2B Solution :

Question no – (1)

Solution :

(a) 10-4

= 1/104

= 1/10000

(b) 10-7

= 1/17

= 1/10000000

(c) 10-8

= 1/108

= 1/100000000

(d) 10-10

= 1/1010

= 1/10000000000

Question no – (2)

Solution :

(a) 5,700,000 in scientific notation,

= 57 × 101000

(b) 8,19,000 in scientific notation,

= 81.90 × 1000

(c) 4,000,000,000 in scientific notation,

= 2020000

(d) 56,000 in scientific notation,

= 560 × 10100

Question no – (3)

Solution :

(a) 0.000053 in scientific notation,

= 53/16

(b) 0.000000084 in scientific notation,

= 84/109

(c) 0.0009 in scientific notation,

= 9/104

(d) 0.0603 in scientific notation,

= 603/104

Question no – (6)

Solution :

(a) Distance form earth to sun is 149600000000

In Standard form,

= 1.496 × 10^11 m

(b) The average diameter of a red blood cell is 0.000007 mm.

In Standard form,

= 7 × 10-6 mm

(c) Diameter of a wire in a computer chip is 0.000003 m.

In Standard form,

= 3 × 10-6 m

(d) Size of a plant cell is 0.00001275 m.

In Standard form,

= 1275 × 10-7 m

Next Chapter Solution :

Updated: June 19, 2023 — 7:36 am