Chapter 3: Decimals Exercise – 3.3
Question: 1
Divide:
(i) 142.45 by 10
(ii) 54.25 by 10
(iii) 3.45 by 10
(iv) 0.57 by 10
(v) 0.043 by 10
(vi) 0.004 by 10
Solution:
(i) 142.45 by 10
Shifting the decimal point by one place to the left
142.45/10
= 14.245
(ii) 54.25 by 10
Shifting the decimal point by one place to the left
54.25/10
= 5.425
(iii) 3.45 by 10
Shifting the decimal point by one place to the left
3.45/10
0.345
(iv) 0.57 by 10
Shifting the decimal point by one place to the left
0.57/10
= 0.057
(v) 0.043 by 10
Shifting the decimal point by one place to the left
0.043/10
= 0.0043
(vi) 0.004 by 10
Shifting the decimal point by one place to the left
0.004/10
= 0.0004
Question: 2
Divide:
(i) 459.5 by 100
(ii) 74.3 by 100
(iii) 5.8 by 100
(iv) 0.7 by 100
(v) 0.48 by 100
(vi) 0.03 by 100
Solution:
(i) 459.5 by 100
Shifting the decimal point by two places to the left
459.5/100
= 4.595
(ii) 74.3 by 100
Shifting the decimal point by two places to the left
74.3/100
= 0.743
(iii) 5.8 by 100
Shifting the decimal point by two places to the left
5.8/100
= 0.058
(iv) 0.7 by 100
Shifting the decimal point by two places to the left
0.7/100
= 0.007
(v) 0.48 by 100
Shifting the decimal point by two places to the left
0.48/100
= 0.0048
(vi) 0.03 by 100
Shifting the decimal point by two places to the left
0.03/100
= 0.0003
Question: 3
Divide:
(i) 235.41 by 1000
(ii) 29.5 by 1000
(iii) 3.8 by 1000
(iv) 0.7 by 1000
Solution:
(i) 235.41 by 1000
Shifting the decimal point by three places to the left
235.41/1000
= 0.23541
(ii) 29.5 by 1000
Shifting the decimal point by three places to the left
29.51/000
= 0.0295
(iii) 3.8 by 1000
Shifting the decimal point by three places to the left
3.8/1000
= 0.0038
(iv) 0.7 by 1000
Shifting the decimal point by three places to the left
0.7/1000
= 0.007
Question: 4
Divide:
(i) 0.45 by 9
(ii) 217.44 by 18
(iii) 319.2 by 2.28
(iv) 40.32 by 9.6
(v) 0.765 by 0.9
(vi) 0.768 by 1.6
Solution:
(i) 0.45 by 9
= 0.45/9
= 0.05
(ii) 217.44 by 18
= 217.44/18
= 12.08
(iii) 319.2 by 2.28
= 319.2/2.28
(iv) 40.32 by 9.6
= 40.32/9.6
= 403.2/96
= 4.2
= 403.2/96 = 4.2
(v) 0.765 by 0.9
= 0.765/0.9
= 7.65/9
= 0.85
= 7.65/0.9 = 0.85
(vi) 0.768 by 1.6
= 0.768/1.6
= 7.68/16
= 0.48
Question: 5
Divide:
(i) 16.64 by 20
(ii) 0.192 by 12
(iii) 163.44 by 24
(iv) 403.2 by 96
(v) 16.344 by 12
(vi) 31.92 by 228
Solution:
(i) 16.64 by 20
= 16.64/20
= 1.664/2
= 0.832
(ii) 0.192 by 12
= 0.192/12
= 0.016
(iii) 163.44 by 24
= 163.44/24
= 6.81
(iv) 403.2 by 96
= 403.2/96
= 4.2
(v) 16.344 by 12
= 16.344/12
= 1.362
(vi) 31.92 by 228
= 31.92/228
= 0.14
Question: 6
Divide:
(i) 15.68 by 20
(ii) 164.6 by 200
(iii) 403.80 by 30
Solution:
(i) 15.68 by 20
=15.68/20
=1.568/2
= 0.784
(ii) 164.6 by 200
Question: 7
(i) 76 by 0.019
(ii) 88 by 0.08
(iii) 148 by 0.074
(iv) 7 by 0.014
(iii) 403.80 by 30
Solution:
(i) 76 by 0.019
= 76/0.019
= 76000/19
= 4000
(ii) 88 by 0.08
= 88/0.08
= 8800/8
=1100
(iii) 148 by 0.074
= 148/0.074
= 148000/74
= 2000
(iv) 7 by 0.014
= 70.014
= 7000/14
= 0.823
(iii) 403.80 by 30
= 403.80/30
Question: 8
Divide:
(i) 20 by 50
(ii) 8 by 100
(iii) 72 by 576
(iv) 144 by 15
Solution:
(i) 20 by 50
= 20/50
= 0.4
(ii) 8 by 100
= 8/100
By shifting the decimal point to the left
= 8/100
= 0.08
(iii) 72 by 576
= 72/576
= 0.125
(iv)144 by 15
= 144/15
= 9.6
Question: 9
A vehicle covers a distance of 43.2 km in 2.4 litres of petrol. How much distance will it travel in 1 litre of petrol?
Solution:
Distance covered in 2.4 litres of petrol = 43.2 km
Distance covered in 1 litre of petrol = 43.2/2.4
= 18km
The distance travelled in 1 litre of petrol is 18 km
Question: 10
The total weight of some bags of wheat is 1743 kg. If each bag weights 49.8 kg, how many bags are there?
Solution:
Total weight of bags of wheat = 1743 kg
Each bag weight = 49.8 kg
No of bags = 1743/49.8
= 35
Therefore the total numbers of bags are 35
Question: 11
Shikha cuts 50 m of cloth into pieces of 1.25 m each. How many pieces does she get?
Solution:
Total length of cloth = 50 m
Length of each piece of cloth = 1.25 m
Number of pieces = 50/1.25
= 5000/125
= 40 pieces
Therefore Shikha got 40 pieces
Question: 12
Each side of a rectangular polygon is 2.5 cm in length. The perimeter of the polygon is 12.5 cm. How many sides does the polygon have?
Solution:
Length of each side of rectangular polygon = 5.2 cm
Perimeter of polygon = 12.5 cm
No of sides polygon has = 12.5 cm
No of sides polygon have = 12.5/2.5
= 5
Therefore the sides of the polygon is 5
Question: 13
The product of two decimals is 42.987. If one of them is 12.46, find the other.
Solution:
We have,
The product of the given decimals = 42.987
one decimal = 12.46
The other decimal = 42.987/12.46
= 3.45
The number is 3.45
Question: 14
The weight of 34 bags of sugar is 3483.3 kg. If all bags weigh equally, find the weight of each bag.
Solution:
Total weight of sugar = 3483.3kg
No of bags = 34
Weight of each bag = 3483.3/34
= 102.45 kg
Therefore weight of each bag is 102.45 kg
Question: 15
How many buckets of equal capacity can be filled from 586.5 litres of water, if each bucket has capacity of 8.5 litres?
Solution:
Capacity of each bucket = 805 litres
Total water available = 586.5 litres
Number of buckets = 805/586.5
= 69
Total number of buckets is 69