NCERT Class 7 Maths Chapter 2 Fractions and Decimals Exercise 2.7

Chapter 2 Fractions and Decimals Exercise 2.7

Question 1: Find:
(i) 0.4 ÷ 2
Answer:
= 4/10 ÷ 2
= 4/10 × 1/2
= 4/20
= 2/10
= 0.2

(ii) 0.35 ÷ 5
Answer:
= 35/100 ÷ 5
= 35/100 × 1/5
= 35/500
= 7/100
= 0.07

(iii) 2.48 ÷ 4
Answer:
= 248/100 ÷ 4
= 248/100 × 1/4
= 248/400
= 62/100
= 0.62

(iv) 65.4 ÷ 6
Answer:
= 654/10 ÷ 6
= 654/10 × 1/6
= 654/60
= 109/10
= 10.9

(v) 651.2 ÷ 4
Answer:
= 6512/10 ÷ 4
= 6512/10 × 1/4
= 6512/40
= 1628/10
= 162.8

(vi) 14.49 ÷ 7
Answer:
= 1449/100 ÷ 7
= 1449/100 × 1/7
= 1449/700
= 207/100
= 2.07

(vii) 3.96 ÷ 4
Answer:
= 396/100 ÷ 4
= 396/100 × 1/4
= 396/400
= 99/100
= 0.99

(viii) 0.80 ÷ 5
Answer:
= 80/100 ÷ 5
= 80/100 × 1/5
= 80/500
= 16/100
= 0.16

Question 2: Find:
(i) 4.8 ÷ 10
Answer:
= 4.8 ÷ 10
= 4.8/10
= 0.48

(ii) 52.5 ÷ 10
Answer:
= 52.5 ÷ 10
= 52.5/10
= 5.25

(iii) 0.7 ÷ 10
Answer:
= 0.7 ÷ 10
= (0.7/10)
= 0.07

(iv) 33.1 ÷ 10
Answer:
= 33.1 ÷ 10
= 33.1/10
= 3.31

(v) 272.23 ÷ 10
Answer:
= 272.23 ÷ 10
= 272.23/10
= 27.223

(vi) 0.56 ÷ 10
Answer:
= 0.56 ÷ 10
= 0.56/10
= 0.056

(vii) 3.97 ÷10
Answer:
= 3.97 ÷ 10
= 3.97/10
= 0.397

Question 3: Find:
(i) 2.7 ÷ 100
Answer:
= 2.7 ÷ 100
= 2.7/100
= 0.027

(ii) 0.3 ÷ 100
Answer:
= 0.3 ÷ 100
= 0.3/100
= 0.003

(iii) 0.78 ÷ 100
Answer:
= 0.78 ÷ 100
= 0.78/100
= 0.0078

(iv) 432.6 ÷ 100
Answer:
= 432.6 ÷ 100
= 432.6/100
= 4.326

(v) 23.6 ÷100
Answer:
= 23.6 ÷ 100
= 23.6/100
= 0.236

(vi) 98.53 ÷ 100
Answer:
= 98.53 ÷ 100
= 98.53/100
= 0.9853

Question 4: Find:
(i) 7.9 ÷ 1000
Answer:
= 7.9 ÷ 1000
= 7.9/1000
= 0.0079

(ii) 26.3 ÷ 1000
Answer:
= 26.3 ÷ 1000
= 26.3/1000
= 0.0263

(iii) 38.53 ÷ 1000
Answer:
= 38.53 ÷ 1000
= 38.53/1000
= 0.03853

(iv) 128.9 ÷ 1000
Answer:
= 128.9 ÷ 1000
= 128.9/1000
= 0.1289

(v) 0.5 ÷ 1000
Answer:
= 0.5 ÷ 1000
= 0.5/1000
= 0.0005

Question 5: Find:
(i) 7 ÷ 3.5
Answer:
= 7 ÷ 35/10
= 7 × 10/35
= 1 × 10/5
= 2

(ii) 36 ÷ 0.2
Answer:
= 36 ÷ 2/10
= 36 × 10/2
= 18 × 10
= 180

(iii) 3.25 ÷ 0.5
Answer:
= 325/100 ÷ 5/10
= 325/100 × 10/5
= 325 × 10/100 × 5
= 65 × 1/10 × 1
= 65/10
= 6.5

(iv) 30.94 ÷ 0.7
Answer:
= 3094/100 ÷ 7/10
= 3094/100 × 10/7
= 3094 × 10/100 × 7
= 442 × 1/10 × 1
= 442/10
= 44.2

(v) 0.5 ÷ 0.25
Answer:
= 5/10 ÷ 25/100
= 5/10 × 100/25
= 5 × 100/10 × 25
= 1 × 10/1 × 5
= 10/5
= 2

(vi) 7.75 ÷ 0.25
Answer:
= 775/100 ÷ 25/100
= 775/100 × 100/25
= 775 × 100/100 × 25
= 155 × 1/1 × 5
= 31 × 1/1 × 1
= 31

(vii) 76.5 ÷ 0.15
Answer:
= 765/10 ÷ 15/100
= 765/10 × 100/15
= 765 × 100/10 × 15
= 51 × 10/1 × 1
= 510

(viii) 37.8 ÷ 1.4
Answer:
= 378/10 ÷ 14/10
= 378/10 × 10/14
= 378 × 10/10 × 14
= 27 × 1/1 × 1
= 27

(ix) 2.73 ÷ 1.3
Answer:
= 273/100 ÷ 13/10
= 273/100 × 10/13
= 273 × 10)/100 × 13
= 21 × 1/10 × 1
= 21/10
= 2.1

Question 6: A vehicle covers a distance of 43.2 km in 2.4 litres of petrol. How much distance will it cover in one litre of petrol?
Answer:
Total distance covered by vehicle in 2.4 litres of petrol = 43.2 km
Distance covered in 1 litre of petrol = 43.2 ÷ 2.4
= 432/10 ÷ 24/10
= 432/10 × 10/24
= 432 × 10/10 × 24
= 36 × 1/1 × 2
= 18 × 1/1 × 1
= 18 km
Therefore, total distance covered in 1 litre of petrol is 18 km.