RD Sharma Solutions Class 7 Ratio And Proportion Exercise 9.2

RD Sharma Class 7 Solutions Chapter 9 Ex 9.2 PDF Free Download

RD Sharma Solutions Class 7 Chapter 9 Exercise 9.2

Exercise 9.2

Q1. Which ratio is larger in the following pairs?

(i) 3:4 or 9:16

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

We have

\(\frac{3}{4}\\=\frac{3\times4}{4\times4}\\=\frac{12}{16}\)

And

\(\frac{9}{16}=\frac{9}{16}\)

Clearly

\(12> 9\\ Therefore\;\frac{3}{4}> \frac{9}{16}\)

 

(ii) 15:16 or 24:25

Now LCM of 16 and 25 is 400

We have

\(15:16=\frac{15\times25}{16\times25}\\=\frac{375}{400}\)

\(24:25=\frac{24\times16}{25\times16}\\=\frac{384}{400}\)

\(\frac{384}{400}> \frac{375}{400}\\ \frac{15}{16}< \frac{24}{25}\)

(iii) 4:7 or 5:8

LCM of 7 and 8 is 56

\(4:7=\frac{4\times8}{7\times8}\\=\frac{32}{56}\)

\(5:8=\frac{5\times7}{8\times7}\\=\frac{35}{56}\)

\(\frac{35}{56}> \frac{32}{56}\\ \frac{5}{8}> \frac{4}{7}\)

5:8>4:7

(iv) 9:20 or 8:13

LCM of 20 and 13 is 260

\(9:20=\frac{9\times13}{20\times13}\\=\frac{160}{260}\)

\(8:13=\frac{8\times20}{13\times20}\\=\frac{117}{260}\)

\(\frac{160}{260}> \frac{117}{260}\\ \frac{8}{13}> \frac{9}{20}\)

(v) 1:2 or 13:27

LCM of 2 and 27 is 54

\(1:2=\frac{1\times27}{2\times27}\\=\frac{27}{54}\)

\(13:27=\frac{13\times2}{27\times2}\\=\frac{26}{54}\)

\(\frac{27}{54}> \frac{26}{54}\\ \frac{1}{2}> \frac{13}{27}\)

Q2. Give the equivalent ratios of 6:8.

Equivalent ratios of 6:8

\(\frac{6\times2}{8\times2}=\frac{12}{16}\) (By multiplying numerator and denominator by 2)

=6:8

\(\frac{\frac{6}{2}}{\frac{8}{2}}=\frac{3}{4}=3:4\) (By dividing numerator and denominator by 2)

Two equivalent ratios

3:4=12:16

Q3. Fill in the following blanks: \(\frac{12}{20}=\frac{….}{5}=\frac{9}{….}\)

  \(\frac{12}{20}=\frac{x}{5}\\ x=\frac{60}{20}\\ x=3\\ \frac{12}{20}=\frac{9}{y}\\ 12y=180\\ y=\frac{180}{12}\\ y=15\\\)

x=3 and y=15

Leave a Comment

Your email address will not be published. Required fields are marked *