Chapter 9: Ratio, Proportion and Unitary Method Exercise 9.2

Ratio, Proportion and Unitary Method – Exercise 9.2 – Q.1

(i) 3 : 4 (or) 9 : 16

Writing the given ratios as fractions, we have

Now L.C.M of 4 and is is 16

Making the denominaator of each fraction

equal to 16, we have

Clearly 12 >9

(ii) 15 : 16 or 24 : 24

Writing the given ratio as fractions, we have

L.C.M of 25 & 16 is = 400

Making the denominator of each fraction equal to 400, we have

clearly 384 > 375

(iii) 4 :7 or 5 : 8

Now, LCM of 7 and 8 is 56.

Clearly 35 > 32

(iv) 9 : 20 or 8 : 13.

Now, LCM of 20 and 13 is 260

Clearly 160 > 117

(v) 1 : 2 or 13 : 27

Now, LCM of 2 and 27 is 54

 

Ratio, Proportion and Unitary Method – Exercise 9.2 – Q.2

i.e. have.

∴  3 : 4 is an equivalent ratio of 6 : 15

So, 12 : 16 is an equivalent ratios of 6:8. Hence, 3 : 4 and 12 : 16 are equivalent ratios of 6 : 8.

 

Ratio, Proportion and Unitary Method – Exercise 9.2 – Q.3

In order to find the first missing number, we consider the denominator 20 and 35

LCM of 20 and 5 is 20.

We have 20 ÷ 4 = 4.

So, we divide the Nr or of 12/20 by 4 to get

Hence, first missing number is 3, consequently the second ratio is 3/5

To find the second missing number, we consider

We have 9 ÷ 3 = 3, so we multiply the nr ∆ or of 3/5 by 3 to get

Hence, the second missing number is 15.