Exercise 12.2 - Chapter 12 - Ratio and proportion - Ncert Solutions class 6 - Maths
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Question 1:
Determine if the following are in proportion.
(a) 15, 45, 40, 120 (b) 33, 121, 9, 96
(c) 24, 28, 36, 48 (d) 32, 48, 70, 210
(e) 4, 6, 8, 12 (f) 33, 44, 75, 100
Answer:
(a) 15, 45, 40, 120
Therefore, 15: 45 = 40: 120
Hence, these are in proportion.
(b) 33, 121, 9, 96
Therefore, 33: 121 ≠ 9: 96
Hence, these are not in proportion.
(c) 24, 28, 36, 48
Therefore, 24: 28 ≠ 36: 48
Hence, these are not in proportion.
(d) 32, 48, 70, 210
Therefore, 32: 48 ≠ 70: 210
Hence, these are not in proportion.
(e) 4, 6, 8, 12
Therefore, 4: 6 = 8: 12
Hence, these are in proportion.
(f) 33, 44, 75, 100
Therefore, 33: 44 = 75: 100
Hence, these are in proportion.
Question 2:
Write True (T) or False (F) against each of the following statements:
(a) 16:24::20:30 (b) 21:6::35:10
(c) 12:18::28:12 (d) 8:9::24:27
(e) 5.2:3.9::3:4 (f) 0.9:0.36::10:4
Answer:
(a) 16: 24:: 20: 30
Therefore, 16: 24 = 20: 30
Hence, True
(b) 21: 6:: 35: 10
Therefore, 21: 6 = 35: 10
Hence, True
(c) 12: 18:: 28: 12
Therefore, 12: 18 ≠ 28: 12
Hence, False
(d) 8: 9:: 24: 27
As
,
Therefore, True
(e) 5.2: 3.9:: 3: 4
As 
,
Therefore, 5.2: 3.9 ≠ 3: 4
Hence, False
(f) 0.9: 0.36:: 10: 4
Therefore, 0.9: 0.36 = 10: 4
Hence, True
Question 3:
Are the following statements true?
(a) 40 persons: 200 persons = Rs 15: Rs 75
(b) 7.5 litres: 15 litres = 5 kg: 10 kg
(c) 99 kg: 45 kg = Rs 44: Rs 20
(d) 32 m: 64 m = 6 sec: 12 sec
(e) 45 km: 60 km = 12 hours: 15 hours
Answer:
(a) 40 persons: 200 persons = Rs 15: Rs 75
True
(b) 7.5 l: 15 l = 5 kg: 10 kg
True
(c) 99 kg: 45 kg = Rs 44: Rs 20
True
(d) 32 m: 64 m = 6 sec: 12 sec
True
(e) 45 km: 60 km = 12 hrs: 15 hrs
False
Question 4:
Determine if the following ratios form a proportion. Also, write the middle terms and extreme terms where the ratios form a proportion.
(a) 25 cm: 1 m and Rs 40 : Rs 160
(b) 39 litres: 65 litres and 6 bottles: 10 bottles
(c) 2 kg: 80 kg and 25 g: 625 g
(d) 200 mL: 2.5 litre and Rs 4: Rs 50
Answer:
(a) 25cm: 1 m and Rs 40: Rs 160
25 cm =
= 0.25 m
Yes. These are in proportion.
Middle terms are 1m, Rs 40.
Extreme terms are 25 cm, Rs 160.
(b) 39 l: 65 l and 6 bottles: 10 bottles
Yes. These are in proportion.
Middle terms are 65 l, 6 bottles.
Extreme terms are 39 l, 10 bottles.
(c) 2 kg: 80 kg and 25g: 625 g
No. These are not in proportion.
(d) 200 mL: 2.5 l and Rs 4: Rs 50
1 l = 1000 mL
2.5 l = 2500 mL
Yes. These are in proportion.
Middle terms are 2.5 l, Rs 4.
Extreme terms are 200 mL, Rs 50.
