RS Aggarwal Class 7 Mathematics Third Chapter Decimals Exercise 3C Solution

RS Aggarwal Class 7 Mathematics Third Chapter Decimals Exercise 3C Solution

EXERCISE 3C

(1) Find the product:

(i) 73.92 × 10 = 739.2

(ii) 7.54 × 10 = 75.4

(iii) 84.003 × 10 = 840.03

(iv) 0.83 × 10 = 8.3

(v) 0.7 × 10 = 7

(vi) 0.032 × 10 = 0.32

(2) Find the product:

(i) 2.397 × 100 = 239.7

(ii) 6.83 × 100 = 683

(iii) 2.9 × 100 = 290

(iv) 0.08 × 100 = 8

(v) 0.6 × 100 = 60

(vi) 0.003 × 100 = 0.3

(3) Find the product:

(i) 6.7314 × 1000 = 6731.4

(ii) 0.182 × 1000 = 182

(iii) 0.076 × 1000 = 76

(iv) 6.25 × 1000 = 6250

(v) 4.8 × 1000 = 4800

(vi) 0.06 × 1000 = 60

(4) Find the product:

(i) 5.4 × 16

(ii) 3.65 × 19

(iii) 0.854 × 12

(iv) 36.73 × 48

(v) 4.125 × 86

(vi) 104.06 × 75

(vii) 6.032 × 124

(viii) 0.0146 × 69

(ix) 0.00125 × 327

(5) Find the product:

(i) 7.6 × 2.4

(ii) 3.45 × 6.3

(iii) 0.54 × 0.27

(iv) 0.568 × 4.9

(v) 6.54 × 0.09

(vi) 3.87 × 1.25

(vii) 0.06 × 0.38 = 0.0228

(viii) 0.623 × 0.75 = 0.46725

(ix) 0.014 × 0.46 = 0.00644

(x) 54.5 × 1.76 = 95.920

(xi) 0.045 × 2.4 = 0.1080

(xii) 1.245 × 6.4 = 7.9680

(6) Find the product:

(i) 13 × 1.3 × 0.13

= 16.9 × 0.13

= 2.197

(ii) 2.4 × 1.5 × 2.5

= 3.6 × 2.5

= 9

(iii) 0.8 × 3.5 × 0.05

= 2.8 × 0.05

= 0.14

(iv) 0.2 × 0.02 × 0.0002

= 0.004 × 0.0002

= 0.0000008

(v) 11.1 × 1.1 × 0.11

= 12.21 × 0.11

= 1.3431

(vi) 2.1 × 0.21 × 0.021

= 0.441 × 0.021

= 0.006261

(7) Evaluate:

(i) (1.2)²

= 1.2 × 1.2

= 1.44

(ii) (0.7)²

= 0.7 × 0.7

= 0.49

(iii) (0.04)²

= 0.04 × 0.04

= 0.0016

(iv) (0.11)²

= 0.11 × 0.11

= 0.0121

(8) Evaluate:

(i) (0.3)³

= 0.3 × 0.3 × 0.3

= 0.027

(ii) (0.05)³

= 0.05 × 0.05 × 0.05

= 0.000125

(iii) (1.5)³

= 1.5 × 1.5 × 1.5

= 3.375

(9) A bus can cover 62.5 km in one hour. How much distance can it cover in 18 hours?

Solution: 62.5 × 18 = 1125 km

(10) A tin of oil weighs 16.8 kg. What is the weight of 45 such tins?

Solution: 45 × 16.8 = 756 kg

(11) A bag of wheat weighs 97.8 kg. How much wheat is contained in 500 such bags?

Solution: 500 × 97.8 = 48900 kg

(12) Find the weight of 16 bags of sugar, each weighing 48.450 kg.

Solution: 48.450 × 16 = 775.2 kg

(13) A small bottle holds 0.845 kg of sauce. How many kg of jam will be there in 72 such bottles?

Solution: 0.845 × 72 = 60.84 kg

(14) A bottle holds 925 g of jam. How many kg of jam will be there in 25 such bottles?

Solution: 925 × 25 = 23125 g = 23.125 kg

(15) If one drum can hold 16.850 litres of oil, how many litres can 48 such drums hold?

Solution: 16.850 × 48 = 808.800 litres

(16) 1 kg of rice costs Rs 56.80. What is the cost of 16.25 kg rice?

Solution: 56.80 × 16.25 = Rs 923

(17) 1 metre of cloth costs Rs 108.50. What is the cost of 18.5 metres of this cloth?

Solution: 108.50 × 18.5 = Rs 2007.25

(18) A car can cover a distance of 8.6 km on one litres of petrol. How far can it go on 36.5 litres of petrol?

Solution: 36.5 × 8.6 = 313.900 km

(19) A taxi driver charges Rs 9.80 per km. How much will he charge for a journey of 106.5 km?

Solution: 106.5 × 9.80 = Rs 1043.70