Kavi’s house is $\frac{17}{8} \mathrm{km}$ away from her school. A temple lies $\frac{8}{5} \mathrm{km}$ from her house in the direction of the school. Find the distance between the temple and her school. 

Distance between house and school $=\frac{17}{8} \mathrm{km}$.

Distance between house and temple $=\frac{8}{5} \mathrm{km}$.

Distance between the temple and Kavi’s school $=\left(\frac{17}{8}-\frac{8}{5}\right) \mathrm{km}$

The LCM of 8 and 5 is 40.

$\begin{array}{rcl} & & \frac{17}{8}-\frac{8}{5}\end{array}$

$\begin{array}{rcl} & =& \frac{17\times 5}{8\times 5}-\frac{8\times 8}{5\times 8}\end{array}$

$\begin{array}{rcl} & =& \frac{85}{40}-\frac{64}{40}\end{array}$

$\begin{array}{rcl} & =& \frac{21}{40}\end{array}$

Thus, the distance between the temple and her school is $\frac{21}{40} \mathrm{km}$.