ML Aggarwal CBSE Solutions Class 8 Math Second Chapter Exponents and Powers Exercise 2.2

ML Aggarwal CBSE Solutions Class 8 Math 2nd Chapter Exponents and Powers Exercise 2.2

(1) (i) 0.0000000000085 = 85×10/1000000000000 = 8.5×10-13

(ii) 0.000000000000942 = 9.42×102/1000000000000000 = 9.42×10-13

(iii) 6020000000000000 = 6.02×102x1013

= 6.02×1015

(iv) 0.00000000837 = 8.37×102/100000000000 = 8.37×10-9

(2) (i) 3.02×10-6 = 302/1000000×102 = 302/108= 0.00000302

(ii) 1.0007×1011 = 1007/10-11x103 = 1007/10-8 = 100700000000

(iii) 5.375×1014 = 5375/10-14x103 = 5375/10-11 = 537500000000000

(iv) 7.579×10-14 = 7579/1014x103 = 7579/107

= 0.00000000000007579

(3) (i) 0.000000000000000000000001673

= 1.673×103/1000000000000000000000000000

= 1.673×103/1027 = 1.673×10-24g

(ii) 0.0016 = 1.6×10/10000 = 1.6×10/104 = 1.6×10-3cm

(iv) 2.2×10/100000000000 = 22×10-9m.

(v) 0.00000000000000000000334

= 3.34×102/100000000000000000000000 = 3.34×102/1023

= 3.34×10-21 tons.

(iii) 0.000003= 3/1000000 = 3×10-6m.

(vi) 1 trillion = 1000,000,000,000 = 1012

(vii) 149, 600, 000, 000m = 1.496×103x108

= 1.496×1011m.

(viii) 300, 000, 000 m/sec = 3×108 m/sec.

(ix) 5970, 000, 000, 000, 000, 000, 000, 000

= 5.97×102x1021 = 5.97×1023 kg.

(x) 1min = 60sec.

1hr = 60min = 60×60 = 3600sec.

1day = 24hr.

Therefore, 1yr = 365day = 24x365hr.

= (24x635x3600) sec

= 31536000 sec.

Therefore, 3yr = 31536000sec x 3

= 94608000 sec.

= 9.4608×104x103

= 9.4608×107 sec.

(xi) We know that –

1 hec = 100000000 cm2

7 hec = 7×100000000 cm2

= 700000000 cm2

= 7.0x10x108

= 7.0×109 cm2 Ans.

(xii) Annual seals = 3 billion 720 million kg.

= 3000000+720000

= 3720000 kg.

= 372×102x10x10x10x10

= 372×106 kg Ans.

(5) We know that –

1lt = 1,000,000mm3

Therefore, 5lt = 5,000,000 mm3

Therefore, the number of blood cells of mm3 = 5.5 ml

Therefore, the number of blood cells 1,000,000 mm3 = 1,000,000×5.5

= 5,5000,00.0

Therefore, the number of blood cells 5,000,000 mm3

= 5,000,000×55,000,00

= 275,000,000,000,000

= 2.75×1012 ml.

(6) Mass of mars = 6.42×1029 kg.

Mass of sun = 1.99×1030 kg.

Therefore, Total mass = (6.42×1029 + (1.99×1030)

= 6.42×1029 + (19.9×10-1x1029)

= (6.42×1029) + (19.9×1029)

= (6.42+19.9) x 1029 = 26.32×1029 kg.

Updated: February 18, 2021 — 5:20 pm

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  1. can u do check your progress also bcz mostly sir will give us questions from there?:)

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