Page 181 - Maths Class 06

Thus, four equivalent ratios of 3 : 5 are:
6 : 10, 9 : 15, 12 : 20, 15 : 25
EX AM PLE 2. Find the ra tio of the fol low ing:
(a) 36 to 84 (b) 33 km to 66 km
(c) 40 minutes to 45 minutes

SOLUTION : (a) 36 to 84 = 36 : 84 = 3 : 7 (b) 33 km to 66 km = 33 : 66 = 1 : 2
(c) 40 minutes to 45 minutes = 40 : 45 = 8 : 9
EX AM PLE 3. Find the ra tio of the fol low ing:
(a) 40 minutes to 1.5 hours (b) 40 cm to 1.5 m

(c) 75 paise to ` 1 (d) 400 mL to 2 L
SOLUTION : (a) 40 min utes to 1.5 hours = 40 min utes to 90 min utes = 40 : 90 = 4 : 9
(b) 40 cm to 1.5 m = 40 cm to 150 cm= 40 : 150 = 4 : 15
(c) 75 paise to ` 1 = 75 paise to 100 paise = 75 : 100 = 3 : 4
(d) 400 mL to 2 L = 400 mL to 2000 mL = 400 : 2000 = 1 : 5
EX AM PLE 4. There are 20 girls and 25 boys in a class.

(a) What is the ratio of number of girls to the number of boys?
(b) What is the ratio of number of girls to the total number of students in the class?
SOLUTION : Number of girls in the class = 20
Number of boys in the class = 25

(a) Ratio of number of girls to the number of boys = 20 : 25 = 4 : 5
(b) Ratio of number of girls to the total number of students in the class
= 20 : (20 + 25) = 20 : 45 = 4 : 9
EX AM PLE 5. In a year, Aakansha earns ` 2,50,000 and saves ` 50,000. Find the ra tio of:
(a) Money that Aakansha saves to the money she earns in a year.

(b) Money that she saves to the money she spends in a year.
SO LU TION : Money Aakansha earns = ` 2,50,000
Money Aakansha saves = ` 50,000

Money Aakansha spends = ` 2,00,000
(a) Money that Aakansha saves to the money she earns = 50 000, : 2,50,000 = 1 : 5
(b) Money that she saves to the money she spends = 50 000, : 2,00,000 = 1 : 4

Exercise12.1

1. Express each one of the following ratios in its simplest form:
(a) 33 : 99 (b) 16 : 18 (c) 25 : 45
(d) 100 : 150 (e) 70 : 42 (f) 17 : 34
(g) 50 : 225 (h) 65 : 91 (i) 450 : 270

(j) 500 : 1000 (k) 87 : 11 (l) 220 : 330
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