Page 97 - New Medley 5 Semester 2

  Two different quantities, say 2 kg and 4 m, cannot be compared using
a ratio.

  Also, 5 L and 50 mL cannot be expressed in the ratio until they are
converted into same units.

Example 1: Find the ratio of the following.

(a) 9 L to 15 L (b) 240 to 400 (c) 2 min to 25 s

9 3
Solution: (a) 9 L to 15 L = = = 3 : 5
15 5
Express the ratio
240 3 80 : 100 in simplest form.
(b) 240 to 400 = = = 3 : 5 80 4
400 5 80 : 100 = = = 4 : 5

(c) Here, the quantities are in 100 5
Hence, 4 : 5 is the simplest
different units, so first, we form of 80 : 100.
convert them in the same

unit.
2 min = 2 × 60 = 120 s

 2 min or 120 s to 25 s

120 24
= 120 : 25 = = = 24 : 5
25 5

Equivalent Ratios

As we get many fractions equivalent to the given fraction, we also have

many ratios equivalent to a common ratio.

Consider the following ratios:
40 2
40 : 60 = = = 2 : 3
60 3

36 2
36 : 54 = = = 2 : 3
54 3

8 2
8 : 12 = = = 2 : 3
12 3

 40 : 60, 36 : 54 and 8 : 12 are equivalent to the ratio 2 : 3.

Thus, we can get a number of equivalent ratios using the concept of
equivalent fractions.

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