Question

Joe walks $4\frac{2}{3}$ km south from his house. Then, he turns around and walks $3\frac{2}{5}$ km towards north. How far is he from his house?

• A. $4\frac{2}{3}$ km
• B. $\frac{121}{15}$ km
• C. $8\frac{1}{15}$ km
• D. $3\frac{4}{5}$ km

Answer 1

The correct option is D $3\frac{4}{5}$ km

Distance between his final point and house
= (Distance travelled towards south - Distance travelled towards north)

$=4\frac{2}{3}-3\frac{2}{5}$

$=\frac{12+2}{3}-\frac{15+2}{5}$

$=\frac{14}{3}-\frac{17}{5}$

$=\frac{14\times 5}{3\times 5}-\frac{17\times 3}{5\times 3}$

$=\frac{70}{15}-\frac{51}{15}$

$=\frac{70-51}{15}$

$=\frac{19}{15}$

$=3\frac{4}{5}$ km

$\therefore$ Joe is $3\frac{4}{5}$ km away from his house.