Fractions and Decimals - Solutions 7

CBSE Class –VII Mathematics
NCERT Solutions
Chapter 2 Fractions and Decimals
 (Ex. 2.7)

Question 1. Find:
(i) 0.4 ÷ 2      
(ii) 0.35 ÷ 5      
(iii) 2.48 ÷ 4      
(iv) 65.4 ÷ 6
(v) 651.2 ÷ 4  
(v) 14.49 ÷ 7  
(vii) 3.96 ÷ 4    
(viii) 0.80 ÷ 5
Answer: (i) 0.4 ÷ 2 = 410×12=210 = 0.2
(ii) 0.35 ÷ 5 = 35100×15=7100 = 0.07
(iii)2.48 ÷ 4 = 248100×14=62100 = 0.62
(iv) 65.4 ÷ 6 = 65410×16=10910 = 10.9
(v) 651.2 ÷ 4 = 651210×14=162810 = 162.8
(vi)14.49 ÷ 7 = 1449100×17=207100 = 2.07
(vii)3.96 ÷ 4 = 396100×14=99100 = 0.99
(viii)0.80 ÷ 5 = 80100×15=16100 = 0.16
Question 2. Find:
(i) 4.8 ÷ 10
(ii) 52.5 ÷ 10
(iii) 0.7 ÷ 10
(iv) 33.1 ÷ 10
(v) 272.23 ÷ 10
(vi) 0.56 ÷ 10
(vii) 3.97 ÷ 10
Answer: (i) 4.8 ÷ 10 = 4.810 = 0.48
(ii) 52.5 ÷ 10 = 52.510 = 5.25
(iii) 0.7 ÷ 10 = 0.710 = 0.07
(iv) 33.1 ÷ 10 = 33.110 = 3.31
(v) 272.23 ÷ 10 = 272.2310 = 27.223
(vi) 0.56 ÷ 10 = 0.5610 = 0.056
(vii) 3.97 ÷ 10 = 3.9710 = 0.397
Question 3. Find:
(i) 2.7 ÷ 100
(ii) 0.3 ÷ 100
(iii) 0.78 ÷ 100
(iv) 432.6 ÷ 100
(v) 23.6 ÷ 100
(vi) 98.53 ÷ 100
Answer: (i) 2.7 ÷ 100 = 2710×1100=271000 = 0.027
(ii) 0.3 ÷ 100 = 310×1100=31000 = 0.003
(iii) 0.78 ÷ 100 = 78100×1100=7810000 = 0.0078
(iv) 432.6 ÷ 100 = 432610×1100=43261000 = 4.326
(v) 23.6 ÷ 100 = 23610×1100=2361000 = 0.236
(vi) 98.53 ÷ 100 = 9853100×1100=985310000 0.9853
Question 4. Find:
(i) 7.9 ÷ 1000
(ii) 26.3 ÷ 1000
(iii) 38.53 ÷ 1000
(iv) 128.9 ÷ 1000
(v) 0.5 ÷ 1000
Answer: (i) 7.9 ÷ 1000 = 7910×11000=7910000 = 0.0079
(ii) 26.3 ÷ 1000 = 26310×11000=26310000 = 0.0263
(iii) 38.53 ÷ 1000 = 3853100×11000=3853100000 = 0.03853
(iv) 128.9 ÷ 1000 = 128910×11000=128910000 = 0.1289
(v) 0.5 ÷ 1000 = 510×11000=510000 = 0.0005
 Question 5. Find:
(i) 7 ÷ 3.5
(ii) 36 ÷ 0.2
(iii) 3.25 ÷ 0.5
(iv) 30.94 ÷ 0.7
(v) 0.5 ÷ 0.25
(vi) 7.75 ÷ 0.25
(vii) 76.5 ÷ 0.15
(viii) 37.8 ÷ 1.4
(ix) 2.73 ÷ 1.3
Answer: (i) 7 ÷ 3.5 = 7÷3510=7×1035=105 = 2
(ii) 36 ÷ 0.2 = 36÷210=36×102= 18 x 10 = 180
(iii) 3.25 ÷ 0.5 = 325100÷510=325100×105=6510 = 6.5
(iv) 30.94 ÷ 0.7 = 3094100÷710=3094100×107=44210 = 44.2
(v) 0.5 ÷ 0.25 = 510÷25100=510×10025=105 = 2
(vi) 7.75 ÷ 0.25 = 775100÷25100=775100×10025 = 31
(vii) 76.5 ÷ 0.15 = 76510÷15100=76510×10015 = 51 x 10 = 510
(viii) 37.8 ÷ 1.4 = 37810÷1410=37810×1014 = 27
(ix) 2.73 ÷ 1.3 = 273100÷1310=273100×1013=2110 = 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 petrol?
Answer In 2.4 litres of petrol, distance covered by the vehicle = 43.2 km
 In 1 litre of petrol, distance covered by the vehicle = 43.2 ÷ 2.4
43210÷2410 = 43210×1024
= 18 km
Thus, it covered 18 km distance in one litre of petrol.