Question

Satpal walks$\frac{2}{3}km$ from a place$P$, towards the east, and then from there$1\frac{5}{7}km$ towards the west. Where will he be now from$P$?

Answer 1

Given,

Satpal walks$\frac{2}{3}km$ from a place$P$, towards the east,

and then from there$1\frac{5}{7}km$ towards the west.

Let us denote the distance traveled east by a positive sign. So the distance towards the west would be denoted by a negative sign.

Thus, the distance of Satpal from the place $P$would be,

$$\begin{gathered} =\frac{2}{3}+\left(-1\frac{5}{7}\right)=\frac{2}{3}+\left(\frac{-12}{7}\right) \\ =\frac{2\times 7}{3\times 7}+\frac{-12\times 3}{7\times 3}\left\{LCM\right(7,3)=21\} \\ =\frac{14}{21}+\frac{-36}{21} \\ =\frac{14-36}{21} \\ =\frac{-22}{21}=-1\frac{1}{21}km \end{gathered}$$

The negative sign shows Satpal is in the west direction from $P$

Hence, Satpal is at a distance from$1\frac{1}{21}km$ the west.