please answer this of class 9 th chapter 4 ratio and proportion
Answers
Question 2:
Find the reduced form of the ratio of the first quantity to second quantity.
(i) 700 rs, 308 rs (ii) 14 rs, 12 rs. 40 paise. (iii) 5 litre, 2500 ml (iv) 3 years 4 months, 5years 8 months (v) 3.8 kg, 1900 gm
(vi) 7 minutes 20 seconds, 5 minutes 6 seconds.
ANSWER:
(i)
Rs 700 : Rs 308 =
700
308
=
700÷28
308÷28
=
25
11
= 25 : 11 (HCF of 700 and 308 = 28)
(ii)
14 rupees = 1400 p
12 rupees 40 paise = 1200 + 40 = 1240 p
∴ 14 rupees : 12 rupees 40 paise = 1400 p : 1240 p =
1400
1240
=
1400÷40
1240÷40
=
35
31
= 35 : 31 (HCF of 1400 and 1240 = 40)
(iii)
5 litre = 5000 mL (1 L = 1000 mL)
∴ 5 litre : 2500 mL = 5000 mL : 2500 mL =
5000
2500
=
5000÷2500
2500÷2500
=
2
1
= 2 : 1 (HCF of 5000 and 2500 = 2500)
(iv)
3 years 4 months = 3 years + 4 months = 3 × 12 + 4 = 36 + 4 = 40 months (1 year = 12 months)
5 years 8 months = 5 years + 8 months = 5 × 12 + 8 = 60 + 8 = 68 months
∴ 3 years 4 months : 5 years 8 months = 40 months : 68 months =
40
68
=
40÷4
68÷4
=
10
17
= 10 : 17 (HCF of 40 and 68 = 4)
(v)
3.8 kg = 3.8 × 1000 = 3800 g (1 kg = 1000 g)
∴ 3.8 kg : 1900 g = 3800 g : 1900 g =
3800
1900
=
3800÷1900
1900÷1900
=
2
1
= 2 : 1 (HCF of 3800 and 1900 = 1900)
(iv)
7 minutes 20 seconds = 7 minutes + 20 seconds = 7 × 60 + 20 = 420 + 20 = 440 seconds (1 minute = 60 seconds)
5 minutes 6 seconds = 5 minutes + 6 seconds = 5 × 60 + 6 = 300 + 6 = 306 seconds
∴ 7 minutes 20 seconds : 5 minutes 6 seconds = 440 seconds : 306 seconds =
440
306
=
440÷2
306÷2
=
220
153
= 220 : 153 (HCF of 220 and 153 = 2)
Page No 61:
Question 3:
Express the following percentages as ratios in the reduced form.
(i) 75 : 100
(ii) 44 : 100