Question

write the descending order of the rational number : 8/7 , -9/8 , 3/2 , 0, 2/5

Answer 1

Answer :

To convert all numbers for same denominator , we find LCM of 7 , 8 , 2 and 5

7 = 1 $\times$ 7

2 = 1 $\times$ 2

5 = 1 $\times$ 5

8 = 2 $\times$ 2 $\times$ 2

LCM ( 7 , 8 , 2 and 5 ) = 2 $\times$ 2 $\times$ 2 $\times$ 5 $\times$ 7 = 280

So,

$$\begin{gathered} \Rightarrow \frac{8}{7}\times \frac{40}{40}=\frac{320}{280}, \\ \Rightarrow -\frac{9}{8}\times \frac{35}{35}=-\frac{315}{280}, \\ \Rightarrow \frac{3}{2}\times \frac{140}{140}=\frac{420}{280}, \\ \mathrm{And} \\ \Rightarrow \frac{2}{5}\times \frac{56}{56}=\frac{112}{280} \\ \mathrm{So}, \\ \frac{420}{280}>\frac{320}{280}>\frac{112}{280}>0>-\frac{315}{280} \\ \mathrm{Therefore}, \\ \frac{\mathbf{3}}{\mathbf{2}}\mathbf{}\mathbf{>}\mathbf{}\frac{\mathbf{8}}{\mathbf{7}}\mathbf{}\mathbf{>}\mathbf{}\frac{\mathbf{2}}{\mathbf{5}}\mathbf{}\mathbf{>}\mathbf{}\mathbf{0}\mathbf{}\mathbf{>}\mathbf{}\mathbf{-}\frac{\mathbf{9}}{\mathbf{8}}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{(}\mathbf{}\mathbf{Ans}\mathbf{}\mathbf{)} \end{gathered}$$