Selina Concise Class 6 Math Chapter 11 Ratio, Proportion And Arithmetic Problems Exercise 11A Solution
EXERCISE 11A
(1) Express each of the following ratios in its simplest form:
(a) (i) 4 : 6 = 2 : 3
(ii) 48 : 54
= (48 ÷ 6) : (54 ÷ 6)
= 8 : 9
(iii) 200 : 250
= (200 ÷ 50) : (250 ÷ 50)
= 4 : 5
(b) (i) 5 kg : 800 gm
= 5000 gm : 800 gm
= (5000 ÷ 100) : (800 ÷ 100)
= (50 ÷ 2) : (8 ÷ 2)
= 25 ÷ 4
(ii) 30 cm : 2 m
= 30 cm : 200 cm
= (30 ÷ 10) : (200 ÷ 10)
= 3 : 20
(iii) 3 m : 90 cm
= 300 cm : 90 cm
= (300 ÷ 10) : (90 ÷ 10)
= (30 ÷ 3) : (9 ÷ 3)
= 10 : 3
(iv) x2 : 4x
= (x2 ÷ x) : (4x ÷ x)
= x : 4
= (25 ÷ 5) : (15 ÷ 5)
= 5 : 3
(2) Ratio of the field’s width to its length
= 80 m : 60 m
= (80 ÷ 10) m : (60 ÷ 10) m
= 8 m : 6 m
= (8 ÷ 2) m : (6 ÷ 2) m
= 4 m : 3 m
(3) State, true or false:
(i) False
(ii) True
(iii) True
250 gm : 3000 gm
= (250 ÷ 250) : (3000 : 250)
= 1 : 12
(4) Yes.
15 kg : 35 kg
= (15 ÷ 5) kg : (35 ÷ 5) kg = 3 kg : 7 kg |
6 years : 14 years
= (6 ÷ 2) years : (14 ÷ 2) years = 3 years : 7 years |
(5) Yes.
6 g : 15 g
= (6 ÷ 3) g : (15 ÷ 3) g = 2 g : 5 g |
36 cm : 90 cm
= (36 ÷ 9) cm : (90 ÷ 9) cm = 4 cm : 10 cm = (4 ÷ 2) cm : (10 ÷ 2) cm = 2 cm : 5 cm |
(6) 3.5 m = 350 cm
2.8 m = 280 cm
∴ 350 : 475 : 280
= (350 ÷ 5) : (475 ÷ 5) : (280 ÷ 5)
= 70 : 95 : 56
(7) 5 dozen = (5 × 12) = 60
2 scores = (2 × 20) = 40
∴ 60 : 40
= (60 ÷ 20) : (40 ÷ 20)
= 3 : 2