A person starts from a point P and walks 1 km along a straight line and then turns to his right and walks straight for 2 km. After that, he turns to his left and walks for 3 km to reach a point Q. What is the straight line distance of the point Q from the point P ?<\/p>\n
[amp_mcq option1=”5 km” option2=”2\u221a5 km” option3=”2\u221a6 km” option4=”4\u00b75 km” correct=”option2″]<\/p>\n
Alternatively, assume the first walk of 1 km is along the positive y-axis. The position is (0,1).
\nTurning right from the positive y-axis means moving along the positive x-axis. The walk of 2 km leads to the position (2, 1).
\nTurning left from the positive x-axis means moving along the positive y-axis. The walk of 3 km leads to the position (2, 1+3) = (2, 4).
\nPoint Q is at (2, 4). The distance from P(0,0) to Q(2,4) is $\\sqrt{(2-0)^2 + (4-0)^2} = \\sqrt{2^2 + 4^2} = \\sqrt{4 + 16} = \\sqrt{20} = 2\\sqrt{5}$.
\nIn both common interpretations of direction and turns, the distance is $2\\sqrt{5}$ km.
\n<\/section>\n","protected":false},"excerpt":{"rendered":"
A person starts from a point P and walks 1 km along a straight line and then turns to his right and walks straight for 2 km. After that, he turns to his left and walks for 3 km to reach a point Q. What is the straight line distance of the point Q from … <\/p>\n